Carl had a total of 105 notes. The notes are $2 notes and $5 notes. After he spent 80% of the $2 notes and 75% of the $5 notes on one refrigerator, he was left with 4 times as many $5 notes as $2 notes. How much did the refrigerator cost?

	$2	$5
Before	5x1 = 5 u	4x4 = 16 u
Change	- 4x1 = - 4 u	- 3x4 = - 12 u
After	1x1 = 1 u	1x4 = 4 u
Comparing $2 and $5 in the end	1x1  = 1 u	4x1 = 4 u

80% of $2 notes = ⁸⁰
₁₀₀ of $2 notes = ⁴₅ of $2 notes
75% of $5 notes = ⁷⁵₁₀₀ of $5 notes = ³₄ of $5 notes

The number of $2 notes in the end is repeated.  Make the number of $2 notes the same.  LCM of 1 and 4 is 4.

The number of $5 notes in the end is repeated. Make the number of $5 notes the same. LCM of 1 and 1 is 1.

Number of notes at first
= 5 u + 16 u
= 21 u

21 u = 105

1 u = 105 ÷ 21 = 5

	$2	$5
Number	4 u	12 u
Value	2	5
Total value	8 u	60 u

Value of $2 spent
= 4 u x 2
= 8 u

Value of $5 spent
= 12 u x 5
= 60 u

Price of the refrigerator
= 8 u + 60 u
= 68 u
= 68 x 5
= $340

Answer(s): $340