The least number greater than 16 which, when divided by 4, 6, 8, 12 and 16,…
2024
The least number greater than 16 which, when divided by 4, 6, 8, 12 and 16, leaves a remainder of 2 in each case, is
- A.
46
- B.
48
- C.
50
- D.
56
Attempted by 4 students.
Show answer & explanation
Correct answer: C
Concept: When a number greater than the given divisors must leave the same remainder r on division by each of them, the least such number equals the LCM of the divisors plus r — because the LCM is the smallest number exactly divisible by every divisor (remainder 0 in each case), and adding r shifts every division's remainder from 0 up to r without exceeding any divisor (since r is smaller than each one here).
Application:
The prime factorisations of the divisors are: 4 = 22, 6 = 2 × 3, 8 = 23, 12 = 22 × 3, 16 = 24.
Taking the highest power of each prime that appears -- 24 from 16, and 3 from 6 or 12 -- the LCM = 24 × 3 = 48.
Add the required remainder of 2 to this LCM: 48 + 2 = 50.
Cross-check: Dividing 50 by 4, 6, 8, 12 and 16 gives quotients 12, 8, 6, 4 and 3 respectively — each with a remainder of exactly 2, confirming 50 satisfies the condition for every divisor. The only smaller number satisfying all five conditions simultaneously is 2 itself (48k + 2 for k = 0), but 2 is smaller than every divisor and so is not a meaningful case of division with a nonzero quotient; the least number greater than the divisors is 50.