Olivia had a total of 33 pieces of $5 and $20 notes at first. She spent
35 of the number of $5 notes and received another 9 pieces of $20 notes from her mother. After that, the number of $20 notes she had was
12 of the remaining notes. How much money did Olivia have at first?
|
$5 |
$20 |
Total |
Before |
5 u |
2 u - 9 |
33 |
Change |
- 3 u |
+ 9 |
|
After |
2 u |
|
|
Comparing $5-notes and $20-notes |
1x2 = 2 u |
1x2 = 2 u |
|
The number of $5-notes and $20-notes in the end is the same.
The number of $5-notes in the end is repeated. Make the number of $5-notes in the end the same. LCM of 1 and 2 is 2.
Number of notes at first
= 5 u + 2 u - 9
= 7 u - 9
7 u - 9 = 33
7 u = 33 + 9
7 u = 42
1 u = 42 ÷ 7 = 6
Number of $5-notes at first
= 5 u
= 5 x 6
= 30
Total value of $5-notes at first
= 30 x 5
= $150
Number of $20-notes at first
= 2 u - 9
= 2 x 6 - 9
= 12 - 9
= 3
Total value of $20-notes at first
= 3 x 20
= $60
Amount that Olivia had at first
= 150 + 60
= $210
Answer(s): $210