Elyse had a total of 111 pieces of $10 and $20 notes at first. She spent
58 of the number of $10 notes and received another 10 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 Elyse have at first?
|
$10 |
$20 |
Total |
Before |
8 u |
3 u - 10 |
111 |
Change |
- 5 u |
+ 10 |
|
After |
3 u |
|
|
Comparing $10-notes and $20-notes |
1x3 = 3 u |
1x3 = 3 u |
|
The number of $10-notes and $20-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 3 is 3.
Number of notes at first
= 8 u + 3 u - 10
= 11 u - 10
11 u - 10 = 111
11 u = 111 + 10
11 u = 121
1 u = 121 ÷ 11 = 11
Number of $10-notes at first
= 8 u
= 8 x 11
= 88
Total value of $10-notes at first
= 88 x 10
= $880
Number of $20-notes at first
= 3 u - 10
= 3 x 11 - 10
= 33 - 10
= 23
Total value of $20-notes at first
= 23 x 20
= $460
Amount that Elyse had at first
= 880 + 460
= $1340
Answer(s): $1340