Last Thursday, Daniel withdrew an equal number of $50-notes and $10-notes from the bank. After spending 90 pieces of $50-notes and 21 pieces of $10-notes, the ratio of the remaining $50-notes to $10-notes became 4 : 7.
- How many $50-notes had he left?
- What was the total value of the notes which Daniel withdrew from the bank?
|
$50-notes |
$10-notes |
Before |
4 u + 90 |
7 u + 21 |
Change |
- 90 |
- 21 |
After |
4 u |
7 u |
(a)
Daniel withdrew an equal number of $50-notes and $10-notes from the bank. So, the number of notes of each type is the same.
7 u + 21 = 4 u + 90
7 u - 4 u = 90 - 21
3 u = 69
1 u = 69 ÷ 3 = 23
Number of $50 notes that Daniel had left
= 4 u
= 4 x 23
= 92
(b)
Number of each type of notes that Daniel withdrew
= 92 + 90
= 182
Value of one set of $50-note and 10-note
= 50 + 10
= $60
Total value of the notes that Daniel withdrew
= 60 x 182
= $10920
Answer(s): (a) 92; (b) $10920