1.  A boy multiplied 987 by a certain number and obtained 559981 as his answer. If in the answer both 9 are wrong and the other digits are correct, then the correct answer would be:
A. 553681
B. 555181
C. 555681
D. 556581

Answer: Option C

Explanation:

987 = 3 x 7 x 47

So, the required number must be divisible by each one of 3, 7, 47

553681 --> (Sum of digits = 28, not divisible by 3)

555181 --> (Sum of digits = 25, not divisible by 3)

555681 --> is divisible by 3, 7, 47.