PSLEAt first, Leah had a total of 58 pink and black balloons. 17 black balloons burst. She then increased the number of pink balloons by 70%. After that, Leah had a total of 55 balloons. How many black balloons did she have at first?
|
Pink |
Black |
Total |
Before |
10 u |
|
58 |
Change |
+ 7 u |
- 17 |
- 3 |
After |
17 u |
|
55 |
70100 =
710Decrease in the number of balloons
= 58 - 55
= 3
7 u = 17 - 3
7 u = 14
1 u = 14 ÷ 7 = 2
Number of pink balloons at first
= 10 u
= 10 x 2
= 20
Number of black balloons at first
= 58 - 20
= 38
Answer(s): 38