Last Friday, Sean withdrew an equal number of $20-notes and $10-notes from the bank. After spending 45 pieces of $20-notes and 11 pieces of $10-notes, the ratio of the remaining $20-notes to $10-notes became 7 : 9.
- How many $20-notes had he left?
- What was the total value of the notes which Sean withdrew from the bank?
| |
$20-notes |
$10-notes |
| Before |
7 u + 45 |
9 u + 11 |
| Change |
- 45 |
- 11 |
| After |
7 u |
9 u |
(a)
Sean withdrew an equal number of $20-notes and $10-notes from the bank. So, the number of notes of each type is the same.
9 u + 11 = 7 u + 45
9 u - 7 u = 45 - 11
2 u = 34
1 u = 34 ÷ 2 = 17
Number of $20 notes that Sean had left
= 7 u
= 7 x 17
= 119
(b)
Number of each type of notes that Sean withdrew
= 119 + 45
= 164
Value of one set of $20-note and 10-note
= 20 + 10
= $30
Total value of the notes that Sean withdrew
= 30 x 164
= $4920
Answer(s): (a) 119; (b) $4920
