Linda had a total of 53 pieces of $10 and $20 notes at first. She spent
25 of the number of $10 notes and received another 3 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 Linda have at first?
|
$10 |
$20 |
Total |
Before |
5 u |
3 u - 3 |
53 |
Change |
- 2 u |
+ 3 |
|
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
= 5 u + 3 u - 3
= 8 u - 3
8 u - 3 = 53
8 u = 53 + 3
8 u = 56
1 u = 56 ÷ 8 = 7
Number of $10-notes at first
= 5 u
= 5 x 7
= 35
Total value of $10-notes at first
= 35 x 10
= $350
Number of $20-notes at first
= 3 u - 3
= 3 x 7 - 3
= 21 - 3
= 18
Total value of $20-notes at first
= 18 x 20
= $360
Amount that Linda had at first
= 350 + 360
= $710
Answer(s): $710