The ratio of the number of $2-notes to $5-notes in Lynn's jar was 1 : 4. Lynn exchanged 12 pieces of $5-notes for $2-notes. She then had an equal number of $2-notes and $5-notes. What was the total value of $2-notes and $5-notes in Lynn's jar at first?
|
$2-notes |
$5-notes |
Before |
1 u |
4 u |
Change |
+ 30 |
- 12 |
After |
1 u + 30 |
4 u - 12 |
Value of 12 pieces of $5-notes
= 12 x 5
= $60
Number of $2-notes that Lynn exchanged for
= 60 ÷ 2
= 30
After the exchange, Lynn had an equal number of $2-notes and $5-notes.
4 u - 12 = 1 u + 30
4 u - 1 u = 30 + 12
3 u = 42
1 u = 42 ÷ 3 = 14
Number of $2-notes at first
= 1 u
= 14
Value of $2-notes at first
= 14 x 2
= $28
Number of $5-notes at first
= 4 u
= 4 x 14
= 56
Value of $5-notes at first
= 56 x 5
= $280
Total value of $2-notes and $5-notes at first
= 28 + 280
= $308
Answer(s): $308