Olivia and Betty had a total of $630 at first. After Olivia spent
13 of her money and Betty spent
23 of her money, they had the same amount of money left.
- How much money did Olivia have at first?
- Betty has the same number of $2-notes and $10-notes at first. How many $10-notes did she have at first?
| |
Olivia |
Betty |
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 Olivia and Betty 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 Olivia and Betty had at first
= 3 u + 6 u
= 9 u
9 u = 630
1 u = 630 ÷ 9 = 70
Amount that Olivia had at first
= 3 u
= 3 x 70
= $210
(b)
Amount that Betty had at first
= 6 u
= 6 x 70
= $420
Betty has the same number of $2-note and $10-note at first.
Value of 1 set of $2-note and $10-note
= 2 + 10
= $12
Number of 2-notes
= 420 ÷ 12
= 35
Answer(s): (a) $210; (b) 35
