Last Saturday, Luis withdrew an equal number of $10-notes and $20-notes from the bank. After spending 84 pieces of $10-notes and 19 pieces of $20-notes, the ratio of the remaining $10-notes to $20-notes became 3 : 8.
- How many $10-notes had he left?
- What was the total value of the notes which Luis withdrew from the bank?
| |
$10-notes |
$20-notes |
| Before |
3 u + 84 |
8 u + 19 |
| Change |
- 84 |
- 19 |
| After |
3 u |
8 u |
(a)
Luis withdrew an equal number of $10-notes and $20-notes from the bank. So, the number of notes of each type is the same.
8 u + 19 = 3 u + 84
8 u - 3 u = 84 - 19
5 u = 65
1 u = 65 ÷ 5 = 13
Number of $10 notes that Luis had left
= 3 u
= 3 x 13
= 39
(b)
Number of each type of notes that Luis withdrew
= 39 + 84
= 123
Value of one set of $10-note and 20-note
= 10 + 20
= $30
Total value of the notes that Luis withdrew
= 30 x 123
= $3690
Answer(s): (a) 39; (b) $3690
