The ratio of the number of $2-notes to $10-notes in Yen's handbag was 1 : 4. Yen exchanged 6 pieces of $10-notes for $2-notes. She then had an equal number of $2-notes and $10-notes. What was the total value of $2-notes and $10-notes in Yen's handbag at first?
| |
$2-notes |
$10-notes |
| Before |
1 u |
4 u |
| Change |
+ 30 |
- 6 |
| After |
1 u + 30 |
4 u - 6 |
Value of 6 pieces of $10-notes
= 6 x 10
= $60
Number of $2-notes that Yen exchanged for
= 60 ÷ 2
= 30
After the exchange, Yen had an equal number of $2-notes and $10-notes.
4 u - 6 = 1 u + 30
4 u - 1 u = 30 + 6
3 u = 36
1 u = 36 ÷ 3 = 12
Number of $2-notes at first
= 1 u
= 12
Value of $2-notes at first
= 12 x 2
= $24
Number of $10-notes at first
= 4 u
= 4 x 12
= 48
Value of $10-notes at first
= 48 x 10
= $480
Total value of $2-notes and $10-notes at first
= 24 + 480
= $504
Answer(s): $504
