{"id":84498,"date":"2025-06-01T00:39:35","date_gmt":"2025-06-01T00:39:35","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=84498"},"modified":"2025-06-01T00:39:35","modified_gmt":"2025-06-01T00:39:35","slug":"a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/","title":{"rendered":"A, B and C alone can finish a job in 20, 25 and 30 days, respectively."},"content":{"rendered":"

A, B and C alone can finish a job in 20, 25 and 30 days, respectively. A and B together start doing the job. However, they leave it after 10 days. The remaining part of the job is finished by C alone. How many days did C take to finish the job ?<\/p>\n

[amp_mcq option1=”4 days” option2=”3 days” option3=”5 days” option4=”6 days” correct=”option2″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC CISF-AC-EXE – 2023<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nThe correct answer is 3 days. This is the time C took to complete the remaining part of the job after A and B had worked for 10 days.
\n<\/section>\n
\n– A’s daily work rate = 1\/20 of the job.
\n– B’s daily work rate = 1\/25 of the job.
\n– C’s daily work rate = 1\/30 of the job.
\n– A and B work together for 10 days.
\n– Combined daily work rate of A and B = (1\/20) + (1\/25) = (5\/100) + (4\/100) = 9\/100 of the job per day.
\n– Work done by A and B in 10 days = (9\/100) * 10 = 90\/100 = 9\/10 of the job.
\n– Remaining part of the job = Total job – Work done by A and B = 1 – 9\/10 = 1\/10 of the job.
\n– C finishes the remaining 1\/10 of the job alone.
\n– Time taken by C = Remaining work \/ C’s daily work rate.
\n– Time taken by C = (1\/10) \/ (1\/30) = (1\/10) * 30 = 30\/10 = 3 days.
\n<\/section>\n
\nThis is a standard work and time problem. The key is to calculate the work rate of each individual and the combined work rate when they work together. Then calculate the portion of the job done in a given time, the remaining work, and the time taken to complete the remaining work by the specified person.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

A, B and C alone can finish a job in 20, 25 and 30 days, respectively. A and B together start doing the job. However, they leave it after 10 days. The remaining part of the job is finished by C alone. How many days did C take to finish the job ? [amp_mcq option1=”4 … <\/p>\n

Detailed SolutionA, B and C alone can finish a job in 20, 25 and 30 days, respectively.<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1089],"tags":[1105,1102],"class_list":["post-84498","post","type-post","status-publish","format-standard","hentry","category-upsc-cisf-ac-exe","tag-1105","tag-quantitative-aptitude-and-reasoning","no-featured-image-padding"],"yoast_head":"\nA, B and C alone can finish a job in 20, 25 and 30 days, respectively.<\/title>\n<meta name=\"description\" content=\"The correct answer is 3 days. This is the time C took to complete the remaining part of the job after A and B had worked for 10 days. - A's daily work rate = 1\/20 of the job. - B's daily work rate = 1\/25 of the job. - C's daily work rate = 1\/30 of the job. - A and B work together for 10 days. - Combined daily work rate of A and B = (1\/20) + (1\/25) = (5\/100) + (4\/100) = 9\/100 of the job per day. - Work done by A and B in 10 days = (9\/100) * 10 = 90\/100 = 9\/10 of the job. - Remaining part of the job = Total job - Work done by A and B = 1 - 9\/10 = 1\/10 of the job. - C finishes the remaining 1\/10 of the job alone. - Time taken by C = Remaining work \/ C's daily work rate. - Time taken by C = (1\/10) \/ (1\/30) = (1\/10) * 30 = 30\/10 = 3 days.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"A, B and C alone can finish a job in 20, 25 and 30 days, respectively.\" \/>\n<meta property=\"og:description\" content=\"The correct answer is 3 days. This is the time C took to complete the remaining part of the job after A and B had worked for 10 days. - A's daily work rate = 1\/20 of the job. - B's daily work rate = 1\/25 of the job. - C's daily work rate = 1\/30 of the job. - A and B work together for 10 days. - Combined daily work rate of A and B = (1\/20) + (1\/25) = (5\/100) + (4\/100) = 9\/100 of the job per day. - Work done by A and B in 10 days = (9\/100) * 10 = 90\/100 = 9\/10 of the job. - Remaining part of the job = Total job - Work done by A and B = 1 - 9\/10 = 1\/10 of the job. - C finishes the remaining 1\/10 of the job alone. - Time taken by C = Remaining work \/ C's daily work rate. - Time taken by C = (1\/10) \/ (1\/30) = (1\/10) * 30 = 30\/10 = 3 days.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T00:39:35+00:00\" \/>\n<meta name=\"author\" content=\"rawan239\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"rawan239\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"A, B and C alone can finish a job in 20, 25 and 30 days, respectively.","description":"The correct answer is 3 days. This is the time C took to complete the remaining part of the job after A and B had worked for 10 days. - A's daily work rate = 1\/20 of the job. - B's daily work rate = 1\/25 of the job. - C's daily work rate = 1\/30 of the job. - A and B work together for 10 days. - Combined daily work rate of A and B = (1\/20) + (1\/25) = (5\/100) + (4\/100) = 9\/100 of the job per day. - Work done by A and B in 10 days = (9\/100) * 10 = 90\/100 = 9\/10 of the job. - Remaining part of the job = Total job - Work done by A and B = 1 - 9\/10 = 1\/10 of the job. - C finishes the remaining 1\/10 of the job alone. - Time taken by C = Remaining work \/ C's daily work rate. - Time taken by C = (1\/10) \/ (1\/30) = (1\/10) * 30 = 30\/10 = 3 days.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/","og_locale":"en_US","og_type":"article","og_title":"A, B and C alone can finish a job in 20, 25 and 30 days, respectively.","og_description":"The correct answer is 3 days. This is the time C took to complete the remaining part of the job after A and B had worked for 10 days. - A's daily work rate = 1\/20 of the job. - B's daily work rate = 1\/25 of the job. - C's daily work rate = 1\/30 of the job. - A and B work together for 10 days. - Combined daily work rate of A and B = (1\/20) + (1\/25) = (5\/100) + (4\/100) = 9\/100 of the job per day. - Work done by A and B in 10 days = (9\/100) * 10 = 90\/100 = 9\/10 of the job. - Remaining part of the job = Total job - Work done by A and B = 1 - 9\/10 = 1\/10 of the job. - C finishes the remaining 1\/10 of the job alone. - Time taken by C = Remaining work \/ C's daily work rate. - Time taken by C = (1\/10) \/ (1\/30) = (1\/10) * 30 = 30\/10 = 3 days.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T00:39:35+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/","url":"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/","name":"A, B and C alone can finish a job in 20, 25 and 30 days, respectively.","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T00:39:35+00:00","dateModified":"2025-06-01T00:39:35+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The correct answer is 3 days. This is the time C took to complete the remaining part of the job after A and B had worked for 10 days. - A's daily work rate = 1\/20 of the job. - B's daily work rate = 1\/25 of the job. - C's daily work rate = 1\/30 of the job. - A and B work together for 10 days. - Combined daily work rate of A and B = (1\/20) + (1\/25) = (5\/100) + (4\/100) = 9\/100 of the job per day. - Work done by A and B in 10 days = (9\/100) * 10 = 90\/100 = 9\/10 of the job. - Remaining part of the job = Total job - Work done by A and B = 1 - 9\/10 = 1\/10 of the job. - C finishes the remaining 1\/10 of the job alone. - Time taken by C = Remaining work \/ C's daily work rate. - Time taken by C = (1\/10) \/ (1\/30) = (1\/10) * 30 = 30\/10 = 3 days.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/a-b-and-c-alone-can-finish-a-job-in-20-25-and-30-days-respectively\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CISF-AC-EXE","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-cisf-ac-exe\/"},{"@type":"ListItem","position":3,"name":"A, B and C alone can finish a job in 20, 25 and 30 days, respectively."}]},{"@type":"WebSite","@id":"https:\/\/exam.pscnotes.com\/mcq\/#website","url":"https:\/\/exam.pscnotes.com\/mcq\/","name":"MCQ and Quiz for Exams","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/exam.pscnotes.com\/mcq\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209","name":"rawan239","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","caption":"rawan239"},"sameAs":["https:\/\/exam.pscnotes.com"],"url":"https:\/\/exam.pscnotes.com\/mcq\/author\/rawan239\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/84498","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/comments?post=84498"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/84498\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=84498"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=84498"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=84498"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}