Xuan had 180 more sweets than Cathy. Xuan used
67 of her sweets and Cathy used
23 of her sweets. In the end, Xuan had 3 times as much as Cathy. Find the number of sweets that Cathy had at first.
| |
Xuan |
Cathy |
Comparing Xuan
and Parry at first |
180 more |
|
| Before |
7x3 =
21 u |
3 u |
| Change |
- 6x3 =
- 18 u |
- 2 u |
| After |
1x3 =
3 u |
1 u |
Comparing Xuan
and Parry in the end |
3 u |
1 u |
The number of sweets that Xuan had in the end is repeated. Make the number of sweets that Xuan had in the end the same. LCM of 1 and 3 is 3.
Number of sweets that Xuan had more than Cathy
= 21 u - 3 u
= 18 u
18 u = 180
1 u = 180 ÷ 18 = 10
Number of sweets that Cathy had at first
= 3 u
= 3 x 10
= 30
Answer(s): 30
