The following sequence is generated by dividing 50 by natural numbers :
0, 0, 2, 0, 2, x, 2, 5, …
What is x?
The sequence is generated by “dividing 50 by natural numbers”, implying the inputs are natural numbers n=1, 2, 3, 4, 5, 6, 7, 8, …
Let f(n) be the term in the sequence corresponding to the natural number n.
f(1) = 0
f(2) = 0
f(3) = 2
f(4) = 0
f(5) = 2
f(6) = x
f(7) = 2
f(8) = 5
Let’s analyse the relationship between n and f(n).
Notice the outputs 0, 0, 2, 0, 2, ?, 2, 5.
The inputs are 1, 2, 3, 4, 5, 6, 7, 8.
f(1)=0, f(2)=0, f(4)=0. These inputs (1, 2, 4) are powers of 2 ($1=2^0$, $2=2^1$, $4=2^2$).
f(3)=2, f(5)=2, f(7)=2. These inputs (3, 5, 7) are primes greater than 2.
f(8)=5. This input (8) is $2^3$.
f(6)=x. This input (6) is not a power of 2 and not a prime.
Let’s hypothesize a rule based on the observed pattern:
– If n is a power of 2, $n=2^k$: the output depends on k? f(1)=f($2^0$)=0, f(2)=f($2^1$)=0, f(4)=f($2^2$)=0, f(8)=f($2^3$)=5.
– If n is a prime greater than 2: f(n)=2. (Matches f(3), f(5), f(7)).
– If n is composite and not a power of 2: f(n)=? (Only n=6 in the given range).
Let’s refine the rule based on inputs being powers of 2 vs not powers of 2.
– If n is a power of 2: $n=2^k$. f(1)=0, f(2)=0, f(4)=0, f(8)=5. This still doesn’t follow a simple rule like k, k+c, k^2, etc.
– If n is NOT a power of 2: f(3)=2, f(5)=2, f(7)=2. This strongly suggests f(n)=2 for n which are not powers of 2, with a potential exception for n=8.
Let’s assume the rule is:
f(n) = 2 if n is not a power of 2.
f(n) = 0 if n is a power of 2, except for n=8.
f(8) = 5.
Let’s test this rule:
f(1) = f($2^0$). Power of 2, not 8. Rule says 0. Matches.
f(2) = f($2^1$). Power of 2, not 8. Rule says 0. Matches.
f(3). Not a power of 2. Rule says 2. Matches.
f(4) = f($2^2$). Power of 2, not 8. Rule says 0. Matches.
f(5). Not a power of 2. Rule says 2. Matches.
f(6). Not a power of 2 ($6 = 2 \times 3$). Rule says 2. So x=2.
f(7). Not a power of 2. Rule says 2. Matches.
f(8) = f($2^3$). This is the special case $n=8$. Rule says 5. Matches.
This rule consistently explains the sequence values 0, 0, 2, 0, 2, ?, 2, 5, and predicts x=2.
The number 6 is not a power of 2 ($1, 2, 4, 8, 16, …$). According to the rule, f(6) should be 2.
Therefore, x = 2.
– Look for patterns relating the input number ‘n’ to the output value in the sequence.
– Identify properties of ‘n’ that seem to determine the sequence value (e.g., being a prime, a power of 2, etc.).