If "n" is a natural number, then (6n² + 6n) is always divisible by—
A
by 6 only
B
both by 6 and 12
C
by 12 only
D
only by 18
Correct Option:
B
Explanation
Factor: 6n² + 6n = 6n(n + 1). Two consecutive natural numbers n and n + 1 always include one even number, so n(n + 1) is divisible by 2. Hence the expression contains a factor 6 × 2 = 12, making it always divisible by 12 and therefore also by 6.
