PSLE Tim had 18 more five-dollar notes than ten-dollar notes at first. He exchanged $90 worth of ten-dollar notes for five-dollar notes. How many more five-dollar notes than ten-dollar notes did Tim have after the exchange?
Number |
$5 |
$10 |
Before |
1 u + 18 |
1 u |
Change |
+ 18 |
- 9 |
After |
1 u + 18 + 18 |
1 u - 9 |
Number of ten-dollar notes that Tim exchanged into five-dollar notes
= 90 ÷ 10
= 9
Number of five-dollar notes that Tim received from the exchange
= 90 ÷ 5
= 18
Number of more five-dollar notes than ten-dollar notes
= 18 + 18 + 9
= 45
Answer: 45