Risa and Opal had a total of $1170 at first. After Risa spent
14 of her money and Opal spent
23 of her money, they had the same amount of money left.
- How much money did Risa have at first?
- Opal has the same number of $10-notes and $5-notes at first. How many $5-notes did she have at first?
| |
Risa |
Opal |
Total |
Before |
4 u |
3x3 =
9 u |
13 u |
Change |
- 1 u |
- 2x3 =
- 6 u |
|
After |
3 u |
1x3 =
3 u |
|
(a)
The amount that Risa and Opal had in the end is the same. Make the amount that they each had in the end the same. LCM of 1 and 3 is 3.
Total amount that Risa and Opal had at first
= 4 u + 9 u
= 13 u
13 u = 1170
1 u = 1170 ÷ 13 = 90
Amount that Risa had at first
= 4 u
= 4 x 90
= $360
(b)
Amount that Opal had at first
= 9 u
= 9 x 90
= $810
Opal has the same number of $10-note and $5-note at first.
Value of 1 set of $10-note and $5-note
= 10 + 5
= $15
Number of 10-notes
= 810 ÷ 15
= 54
Answer(s): (a) $360; (b) 54
