13 of Barbara's money was equal to
12 of Tammy's money at first. After Barbara spent $70 and Tammy spent
13 of her money, Barbara had
12 as much money as Tammy.
- How much money did Tammy have at first?
- How much money did Tammy have in the end?
| |
Barbara |
Tammy |
Comparing Barbara
and Tammy at first |
3x3 =
9 u |
2x3 =
6 u |
| Before |
|
3x2 =
6 u |
| Change |
- $70 |
- 1x2 =
- 2 u |
| After |
|
2x2 =
4 u |
Comparing Barbara
and Tammy in the end |
1x2 =
2 u |
2x2 =
4 u |
13 Barbara's money =
12 Tammy's money
Make numerators the same.
13 Barbara's money =
1x12x1 Tammy's money
13 Barbara's money =
12 Tammy's money
Barbara's money : Tammy's money = 3 : 2
The amount that Tammy had at first is repeated. Make the amount that Tammy had at first the same. LCM of 2 and 3 is 6.
Amount that Barbara spent
= 9 u - 2 u
= 7 u
7 u = 70
1 u = 70 ÷ 7 = 10
(a)
Amount that Tammy had at first
= 6 u
= 6 x 10
= $60
(b)
Amount that Tammy had in the end
= 4 u
= 4 x 10
= $40
Answer(s): (a) $60; (b) $40
