Tina had an equal number of $10 and $1 notes. After spending 17 pieces of $1 and 11 pieces of $10 notes, the ratio of the $10 notes to $1 notes left was 3 : 1. Find the value of the notes left.
| |
$10 |
$1 |
| Before |
3 u + 11 |
1 u + 17 |
| Change |
- 11 |
- 17 |
| After |
3 u |
1 u |
Number of $10 notes at first = 3 u + 11
Number of $1 notes at first = 1 u + 17
The number of $10 and $1 notes at first is the same.
3 u + 11 = 1 u + 17
3 u - 1 u = 17 - 11
2 u = 6
1 u = 6 ÷ 2 = 3
Value of $10-notes left
= 3 u x 10
= 3 x 3 x 10
= $90
Value of $1-notes left
= 1 u x 1
= 1 x 3 x 1
= $3
Value of notes left
= 90 + 3
= $93
Answer(s): $93
