PSLEAt first, Leah had a total of 108 red and purple balloons. 18 purple balloons burst. She then increased the number of red balloons by 70%. After that, Leah had a total of 139 balloons. How many purple balloons did she have at first?
|
Red |
Purple |
Total |
Before |
10 u |
|
108 |
Change |
+ 7 u |
- 18 |
+ 31 |
After |
17 u |
|
139 |
70100 =
710Increase in the number of balloons
= 139 - 108
= 31
7 u = 31 + 18
7 u = 49
1 u = 49 ÷ 7 = 7
Number of red balloons at first
= 10 u
= 10 x 7
= 70
Number of purple balloons at first
= 108 - 70
= 38
Answer(s): 38