Last Sunday, Ken withdrew an equal number of $20-notes and $100-notes from the bank. After spending 46 pieces of $20-notes and 13 pieces of $100-notes, the ratio of the remaining $20-notes to $100-notes became 7 : 10.
- How many $20-notes had he left?
- What was the total value of the notes which Ken withdrew from the bank?
| |
$20-notes |
$100-notes |
| Before |
7 u + 46 |
10 u + 13 |
| Change |
- 46 |
- 13 |
| After |
7 u |
10 u |
(a)
Ken withdrew an equal number of $20-notes and $100-notes from the bank. So, the number of notes of each type is the same.
10 u + 13 = 7 u + 46
10 u - 7 u = 46 - 13
3 u = 33
1 u = 33 ÷ 3 = 11
Number of $20 notes that Ken had left
= 7 u
= 7 x 11
= 77
(b)
Number of each type of notes that Ken withdrew
= 77 + 46
= 123
Value of one set of $20-note and 100-note
= 20 + 100
= $120
Total value of the notes that Ken withdrew
= 120 x 123
= $14760
Answer(s): (a) 77; (b) $14760
