Sarah and Ivory had a total of $900 at first. After Sarah spent
13 of her money and Ivory spent
23 of her money, they had the same amount of money left.
- How much money did Sarah have at first?
- Ivory has the same number of $5-notes and $10-notes at first. How many $10-notes did she have at first?
| |
Sarah |
Ivory |
Total |
Before |
3 u |
3x2 =
6 u |
9 u |
Change |
- 1 u |
- 2x2 =
- 4 u |
|
After |
2 u |
1x2 =
2 u |
|
(a)
The amount that Sarah and Ivory had in the end is the same. Make the amount that they each had in the end the same. LCM of 1 and 2 is 2.
Total amount that Sarah and Ivory had at first
= 3 u + 6 u
= 9 u
9 u = 900
1 u = 900 ÷ 9 = 100
Amount that Sarah had at first
= 3 u
= 3 x 100
= $300
(b)
Amount that Ivory had at first
= 6 u
= 6 x 100
= $600
Ivory has the same number of $5-note and $10-note at first.
Value of 1 set of $5-note and $10-note
= 5 + 10
= $15
Number of 5-notes
= 600 ÷ 15
= 40
Answer(s): (a) $300; (b) 40
