Bunuel
For positive integers a and b, when a is divided by b the remainder is 12. If a/b = 32.16, what is the value of b?
A. 25
B. 32
C. 64
D. 75
E. 96
This problem will be best solved using the remainder formula. Let’s first state the remainder formula:
When positive integer a is divided by positive integer b, if integer Q is the quotient and r is the remainder, then a/b = Q + r/b.
In this problem, we are given that when positive integer a is divided by positive integer b, the remainder is 12. So, we can say:
a/b = Q + 12/b
We also are given that a/b = 32.16. Using the remainder formula, we can say:
a/b = 32.16
a/b = 32 + 0.16
a/b = 32 + 16/100
Because Q is always an integer, we see that Q must be 32, and thus the remainder 12/b must be 16/100. We can now equate 12/b to 16/100 and determine the value of b.
12/b = 16/100
12/b = 4/25
12 x 25 = 4b
3 x 25 = b
75 = b
Answer: D