45 of Mary's money was equal to
13 of Ivory's money at first. After Mary spent $78 and Ivory spent
25 of her money, Mary had
13 as much money as Ivory.
- How much money did Ivory have at first?
- How much money did Ivory have in the end?
| |
Mary |
Ivory |
Comparing Mary
and Ivory at first |
5x5 =
25 u |
12x5 =
60 u |
| Before |
|
5x12 =
60 u |
| Change |
- $78 |
- 2x12 =
- 24 u |
| After |
|
3x12 =
36 u |
Comparing Mary
and Ivory in the end |
1x12 =
12 u |
3x12 =
36 u |
45 Mary's money =
13 Ivory's money
Make numerators the same.
45 Mary's money =
1x43x4 Ivory's money
45 Mary's money =
412 Ivory's money
Mary's money : Ivory's money = 5 : 12
The amount that Ivory had at first is repeated. Make the amount that Ivory had at first the same. LCM of 12 and 5 is 60.
Amount that Mary spent
= 25 u - 12 u
= 13 u
13 u = 78
1 u = 78 ÷ 13 = 6
(a)
Amount that Ivory had at first
= 60 u
= 60 x 6
= $360
(b)
Amount that Ivory had in the end
= 36 u
= 36 x 6
= $216
Answer(s): (a) $360; (b) $216
