Question

Mary McDonald makes mugs in Miami. She makes two sizes of mugs: a small mug that she sells for

$2.50 and a large mug that she sells for $5.75. Yesterday Mary made $56. Before she opened her shop in the morning, she had 200 mugs in her inventory. At the end of the day she has 188. How many mugs of
each price did she sell?

Answer 1

4 small

8 large

Explanation:

s - small mug

l - large mug

Yesterday she had 200 at start of day

at end of day 188 left, so she sold 12 mugs

(1) s + l = 12

(2) 2.50s + 5.75l = 56.00

Solve for l in (1)

l = 12 - s

substitute in l = 12 - s into (2)

2.50s + 5.75(12-s) = 56.00

2.50s + 69.00 - 5.75s = 56.00

-3.25s + 69.00 = 56.00

-3.25s = -13.00

s = 4

to find l substitute s = 4 into (1)

4 + l = 12

l = 8