1.  A is 3 years older to B and 3 years younger to C, while B and D are twins. How many years older is C and D?
A. 3
B. 6
C. 9
D. 12

Answer: Option B

Explanation:

Since B and D are twins. So B = D.
Now A = B + 3 and A = C - 3.
Thus, B + 3 = C - 3 ‹=› D + 3 = C - 3 ‹=› C - D = 6.