We bought 85 hats at the store. Blue hats cost $6 and green hats cost $7. The total price was $530. How many green hats did we buy? Choose the correct choice from the following:
A) 36
B) 20
C) 40
D) 42
E) 44

Rationale: let b be the number of blue hats and let g be the number of green hats . b + g = 85 . b = 85 - g . 6 b + 7 g = 530 . 6 ( 85 - g ) + 7 g = 530 . 510 - 6 g + 7 g = 530 . g = 530 - 510 = 20 . the answer is b .
Answer: B