Carl had a total of 198 notes. The notes are $10 notes and $2 notes. After he spent 75% of the $10 notes and 60% of the $2 notes on one washing machine, he was left with 5 times as many $2 notes as $10 notes. How much did the washing machine cost?
|
$10 |
$2 |
Before |
4x2 = 8 u |
5x5 = 25 u
|
Change |
- 3x2 = - 6 u |
- 3x5 = - 15 u
|
After |
1x2 = 2 u |
2x5 = 10 u |
Comparing $10 and $2 in the end |
1x2 = 2 u
|
5x2 = 10 u |
75% of $10 notes =
75
100 of $10 notes =
34 of $10 notes
60% of $2 notes =
60100 of $2 notes =
35 of $2 notes
The number of $10 notes in the end is repeated. Make the number of $10 notes the same. LCM of 2 and 5 is 10.
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.
Number of notes at first
= 8 u + 25 u
= 33 u
33 u = 198
1 u = 198 ÷ 33 = 6
|
$10 |
$2 |
Number |
6 u |
15 u |
Value |
10 |
2 |
Total value |
60 u |
30 u |
Value of $10 spent
= 6 u x 10
= 60 u
Value of $2 spent
= 15 u x 2
= 30 u
Price of the washing machine
= 60 u + 30 u
= 90 u
= 90 x 6
= $540
Answer(s): $540