Hilda had a total of 29 pieces of $100 and $10 notes at first. She spent
27 of the number of $100 notes and received another 7 pieces of $10 notes from her mother. After that, the number of $10 notes she had was
12 of the remaining notes. How much money did Hilda have at first?
|
$100 |
$10 |
Total |
Before |
7 u |
5 u - 7 |
29 |
Change |
- 2 u |
+ 7 |
|
After |
5 u |
|
|
Comparing $100-notes and $10-notes |
1x5 = 5 u |
1x5 = 5 u |
|
The number of $100-notes and $10-notes in the end is the same.
The number of $100-notes in the end is repeated. Make the number of $100-notes in the end the same. LCM of 1 and 5 is 5.
Number of notes at first
= 7 u + 5 u - 7
= 12 u - 7
12 u - 7 = 29
12 u = 29 + 7
12 u = 36
1 u = 36 ÷ 12 = 3
Number of $100-notes at first
= 7 u
= 7 x 3
= 21
Total value of $100-notes at first
= 21 x 100
= $2100
Number of $10-notes at first
= 5 u - 7
= 5 x 3 - 7
= 15 - 7
= 8
Total value of $10-notes at first
= 8 x 10
= $80
Amount that Hilda had at first
= 2100 + 80
= $2180
Answer(s): $2180