Carl had a total of 80 notes. The notes are $2 notes and $5 notes. After he spent 90% of the $2 notes and 80% of the $5 notes on one refrigerator, he was left with 2 times as many $5 notes as $2 notes. How much did the refrigerator cost?

	$2	$5
Before	10x1 = 10 u	5x2 = 10 u
Change	- 9x1 = - 9 u	- 4x2 = - 8 u
After	1x1 = 1 u	1x2 = 2 u
Comparing $2 and $5 in the end	1x1  = 1 u	2x1 = 2 u

90% of $2 notes = ⁹⁰
₁₀₀ of $2 notes = ⁹₁₀ of $2 notes
80% of $5 notes = ⁸⁰₁₀₀ of $5 notes = ⁴₅ 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 2 is 2.

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
= 10 u + 10 u
= 20 u

20 u = 80

1 u = 80 ÷ 20 = 4

	$2	$5
Number	9 u	8 u
Value	2	5
Total value	18 u	40 u

Value of $2 spent
= 9 u x 2
= 18 u

Value of $5 spent
= 8 u x 5
= 40 u

Price of the refrigerator
= 18 u + 40 u
= 58 u
= 58 x 4
= $232

Answer(s): $232