Opal had a total of 11 pieces of $20 and $5 notes at first. She spent
35 of the number of $20 notes and received another 3 pieces of $5 notes from her mother. After that, the number of $5 notes she had was
12 of the remaining notes. How much money did Opal have at first?
|
$20 |
$5 |
Total |
Before |
5 u |
2 u - 3 |
11 |
Change |
- 3 u |
+ 3 |
|
After |
2 u |
|
|
Comparing $20-notes and $5-notes |
1x2 = 2 u |
1x2 = 2 u |
|
The number of $20-notes and $5-notes in the end is the same.
The number of $20-notes in the end is repeated. Make the number of $20-notes in the end the same. LCM of 1 and 2 is 2.
Number of notes at first
= 5 u + 2 u - 3
= 7 u - 3
7 u - 3 = 11
7 u = 11 + 3
7 u = 14
1 u = 14 ÷ 7 = 2
Number of $20-notes at first
= 5 u
= 5 x 2
= 10
Total value of $20-notes at first
= 10 x 20
= $200
Number of $5-notes at first
= 2 u - 3
= 2 x 2 - 3
= 4 - 3
= 1
Total value of $5-notes at first
= 1 x 5
= $5
Amount that Opal had at first
= 200 + 5
= $205
Answer(s): $205