Last Wednesday, John withdrew an equal number of $50-notes and $100-notes from the bank. After spending 102 pieces of $50-notes and 30 pieces of $100-notes, the ratio of the remaining $50-notes to $100-notes became 7 : 10.
- How many $50-notes had he left?
- What was the total value of the notes which John withdrew from the bank?
|
$50-notes |
$100-notes |
Before |
7 u + 102 |
10 u + 30 |
Change |
- 102 |
- 30 |
After |
7 u |
10 u |
(a)
John withdrew an equal number of $50-notes and $100-notes from the bank. So, the number of notes of each type is the same.
10 u + 30 = 7 u + 102
10 u - 7 u = 102 - 30
3 u = 72
1 u = 72 ÷ 3 = 24
Number of $50 notes that John had left
= 7 u
= 7 x 24
= 168
(b)
Number of each type of notes that John withdrew
= 168 + 102
= 270
Value of one set of $50-note and 100-note
= 50 + 100
= $150
Total value of the notes that John withdrew
= 150 x 270
= $40500
Answer(s): (a) 168; (b) $40500