Question

Grace gave her sister a riddle.

I have a number x. I add 15 to twice of x to obtain A. I subtract 4 from x to obtain B. I multiply B by 3 to obtain C. A is equal to C.

Graces sister said the riddle cannot be solved but Grace thought otherwise. Who is right?

Answer 1

27, Grace

Explanation:

2x + 15 = A x-4 = B 3B = C C= 3x-12 3x-12 = 2x + 15

+12 +12

3x=2x+27

x=27

Grace is right