Carl had a total of 38 notes. The notes are $5 notes and $2 notes. After he spent 75% of the $5 notes and 80% of the $2 notes on one gas stove, he was left with 3 times as many $2 notes as $5 notes. How much did the gas stove cost?
|
$5 |
$2 |
Before |
4x1 = 4 u |
5x3 = 15 u
|
Change |
- 3x1 = - 3 u |
- 4x3 = - 12 u
|
After |
1x1 = 1 u |
1x3 = 3 u |
Comparing $5 and $2 in the end |
1x1 = 1 u
|
3x1 = 3 u |
75% of $5 notes =
75
100 of $5 notes =
34 of $5 notes
80% of $2 notes =
80100 of $2 notes =
45 of $2 notes
The number of $5 notes in the end is repeated. Make the number of $5 notes the same. LCM of 1 and 3 is 3.
The number of $2 notes in the end is repeated. Make the number of $2 notes the same. LCM of 1 and 1 is 1.
Number of notes at first
= 4 u + 15 u
= 19 u
19 u = 38
1 u = 38 ÷ 19 = 2
|
$5 |
$2 |
Number |
3 u |
12 u |
Value |
5 |
2 |
Total value |
15 u |
24 u |
Value of $5 spent
= 3 u x 5
= 15 u
Value of $2 spent
= 12 u x 2
= 24 u
Price of the gas stove
= 15 u + 24 u
= 39 u
= 39 x 2
= $78
Answer(s): $78