Carl had a total of 175 notes. The notes are $10 notes and $2 notes. After he spent 90% of the $10 notes and 80% of the $2 notes on one stand mixer, he was left with 5 times as many $2 notes as $10 notes. How much did the stand mixer cost?
|
$10 |
$2 |
Before |
10x1 = 10 u |
5x5 = 25 u
|
Change |
- 9x1 = - 9 u |
- 4x5 = - 20 u
|
After |
1x1 = 1 u |
1x5 = 5 u |
Comparing $10 and $2 in the end |
1x1 = 1 u
|
5x1 = 5 u |
90% of $10 notes =
90
100 of $10 notes =
910 of $10 notes
80% of $2 notes =
80100 of $2 notes =
45 of $2 notes
The number of $10 notes in the end is repeated. Make the number of $10 notes the same. LCM of 1 and 5 is 5.
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
= 10 u + 25 u
= 35 u
35 u = 175
1 u = 175 ÷ 35 = 5
|
$10 |
$2 |
Number |
9 u |
20 u |
Value |
10 |
2 |
Total value |
90 u |
40 u |
Value of $10 spent
= 9 u x 10
= 90 u
Value of $2 spent
= 20 u x 2
= 40 u
Price of the stand mixer
= 90 u + 40 u
= 130 u
= 130 x 5
= $650
Answer(s): $650