Joelle had a total of 43 pieces of $10 and $50 notes at first. She spent
38 of the number of $10 notes and received another 9 pieces of $50 notes from her mother. After that, the number of $50 notes she had was
12 of the remaining notes. How much money did Joelle have at first?
|
$10 |
$50 |
Total |
Before |
8 u |
5 u - 9 |
43 |
Change |
- 3 u |
+ 9 |
|
After |
5 u |
|
|
Comparing $10-notes and $50-notes |
1x5 = 5 u |
1x5 = 5 u |
|
The number of $10-notes and $50-notes in the end is the same.
The number of $10-notes in the end is repeated. Make the number of $10-notes in the end the same. LCM of 1 and 5 is 5.
Number of notes at first
= 8 u + 5 u - 9
= 13 u - 9
13 u - 9 = 43
13 u = 43 + 9
13 u = 52
1 u = 52 ÷ 13 = 4
Number of $10-notes at first
= 8 u
= 8 x 4
= 32
Total value of $10-notes at first
= 32 x 10
= $320
Number of $50-notes at first
= 5 u - 9
= 5 x 4 - 9
= 20 - 9
= 11
Total value of $50-notes at first
= 11 x 50
= $550
Amount that Joelle had at first
= 320 + 550
= $870
Answer(s): $870