Last Updated on May 9, 2023
GMAT OFFICIAL GUIDE DS
Solution:
We are given that all donuts are priced equally and all bagels are priced equally and need to determine the total price of 5 donuts and 3 bagels. Let’s start by defining some variables.
D = the price per donut
B = the price per bagel
Thus we need to determine: 5D + 3B = ?
Statement One Alone:
At the bakery, the total price of 10 donuts and 6 bagels is $12.90.
Using the information in statement one, we can create the following equation:
10D + 6B = 12.90
We can simplify the equation by dividing the entire equation by 2.
5D + 3B = 6.45
Thus, the price for 5 donuts and 3 bagels is $6.45. Statement one alone is sufficient to answer the question. We can eliminate answer choices B, C, and E.
Statement Two Alone:
At the bakery, the price of a donut is $0.15 less than the price of a bagel.
We can express D in terms of B:
D = B – 0.15
Substituting B – 0.15 for D, we get:
5(B – 0.15) + 3B
5B – 0.75 + 3B
8B – 0.75
However, without knowing anything about the price of either D or B, or the total amount spent, we cannot determine the sum of 5D + 3B. Thus, statement two is insufficient.
Answer: A
