[amp_mcq option1=”01:01″ option2=”01:02″ option3=”02:03″ option4=”03:02″ correct=”option2″]<\/p>\n
The correct answer is (b), 1:2.<\/p>\n
Let $x$ be the number of boys and $y$ be the number of girls. We know that the mean height of boys is 60 cm, the mean height of girls is 55 cm, and the mean height of all the students in the class is 57 cm. We can express this mathematically as follows:<\/p>\n
$$\\frac{60x}{x+y} = 57$$
\n$$\\frac{55y}{x+y} = 57$$<\/p>\n
Subtracting the two equations, we get:<\/p>\n
$$5x = 2y$$<\/p>\n
Dividing both sides by 5, we get:<\/p>\n
$$x = \\frac{2y}{5}$$<\/p>\n
Therefore, the ratio of the number of boys to the number of girls is $\\frac{x}{y} = \\frac{2}{5} = 1:2$.<\/p>\n
Option (a), 1:1, is incorrect because the mean height of boys is greater than the mean height of girls. This means that there must be more boys than girls in the class.<\/p>\n
Option (c), 2:3, is incorrect because the mean height of boys is not twice the mean height of girls. This means that the ratio of the number of boys to the number of girls cannot be 2:3.<\/p>\n
Option (d), 3:2, is incorrect because the mean height of boys is not three times the mean height of girls. This means that the ratio of the number of boys to the number of girls cannot be 3:2.<\/p>\n","protected":false},"excerpt":{"rendered":"
[amp_mcq option1=”01:01″ option2=”01:02″ option3=”02:03″ option4=”03:02″ correct=”option2″]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28],"tags":[],"class_list":["post-1275","post","type-post","status-publish","format-standard","hentry","category-statistics","no-featured-image-padding"],"yoast_head":"\n