Last Saturday, Jack withdrew an equal number of $20-notes and $5-notes from the bank. After spending 55 pieces of $20-notes and 15 pieces of $5-notes, the ratio of the remaining $20-notes to $5-notes became 7 : 9.
- How many $20-notes had he left?
- What was the total value of the notes which Jack withdrew from the bank?
| |
$20-notes |
$5-notes |
| Before |
7 u + 55 |
9 u + 15 |
| Change |
- 55 |
- 15 |
| After |
7 u |
9 u |
(a)
Jack withdrew an equal number of $20-notes and $5-notes from the bank. So, the number of notes of each type is the same.
9 u + 15 = 7 u + 55
9 u - 7 u = 55 - 15
2 u = 40
1 u = 40 ÷ 2 = 20
Number of $20 notes that Jack had left
= 7 u
= 7 x 20
= 140
(b)
Number of each type of notes that Jack withdrew
= 140 + 55
= 195
Value of one set of $20-note and 5-note
= 20 + 5
= $25
Total value of the notes that Jack withdrew
= 25 x 195
= $4875
Answer(s): (a) 140; (b) $4875
