PSLE Ethan had 18 more two-dollar notes than ten-dollar notes at first. He exchanged $120 worth of ten-dollar notes for two-dollar notes. How many less ten-dollar notes than two-dollar notes did Ethan have after the exchange?
Number |
$2 |
$10 |
Before |
1 u + 18 |
1 u |
Change |
+ 60 |
- 12 |
After |
1 u + 18 + 60 |
1 u - 12 |
Number of ten-dollar notes that Ethan exchanged into two-dollar notes
= 120 ÷ 10
= 12
Number of two-dollar notes that Ethan received from the exchange
= 120 ÷ 2
= 60
Number of less ten-dollar notes than two-dollar notes
= 18 + 60 + 12
= 90
Answer: 90