The ratio of the number of $2-notes to $5-notes in Marion's jar was 1 : 8. Marion 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 Marion's jar at first?
|
$2-notes |
$5-notes |
Before |
1 u |
8 u |
Change |
+ 30 |
- 12 |
After |
1 u + 30 |
8 u - 12 |
Value of 12 pieces of $5-notes
= 12 x 5
= $60
Number of $2-notes that Marion exchanged for
= 60 ÷ 2
= 30
After the exchange, Marion had an equal number of $2-notes and $5-notes.
8 u - 12 = 1 u + 30
8 u - 1 u = 30 + 12
7 u = 42
1 u = 42 ÷ 7 = 6
Number of $2-notes at first
= 1 u
= 6
Value of $2-notes at first
= 6 x 2
= $12
Number of $5-notes at first
= 8 u
= 8 x 6
= 48
Value of $5-notes at first
= 48 x 5
= $240
Total value of $2-notes and $5-notes at first
= 12 + 240
= $252
Answer(s): $252