Last Monday, Peter withdrew an equal number of $10-notes and $100-notes from the bank. After spending 47 pieces of $10-notes and 17 pieces of $100-notes, the ratio of the remaining $10-notes to $100-notes became 2 : 5.
- How many $10-notes had he left?
- What was the total value of the notes which Peter withdrew from the bank?
| |
$10-notes |
$100-notes |
| Before |
2 u + 47 |
5 u + 17 |
| Change |
- 47 |
- 17 |
| After |
2 u |
5 u |
(a)
Peter withdrew an equal number of $10-notes and $100-notes from the bank. So, the number of notes of each type is the same.
5 u + 17 = 2 u + 47
5 u - 2 u = 47 - 17
3 u = 30
1 u = 30 ÷ 3 = 10
Number of $10 notes that Peter had left
= 2 u
= 2 x 10
= 20
(b)
Number of each type of notes that Peter withdrew
= 20 + 47
= 67
Value of one set of $10-note and 100-note
= 10 + 100
= $110
Total value of the notes that Peter withdrew
= 110 x 67
= $7370
Answer(s): (a) 20; (b) $7370
