PSLEAt first, Leah had a total of 59 red and black balloons. 18 black balloons burst. She then increased the number of red balloons by 80%. After that, Leah had a total of 61 balloons. How many black balloons did she have at first?
|
Red |
Black |
Total |
Before |
5 u |
|
59 |
Change |
+ 4 u |
- 18 |
+ 2 |
After |
9 u |
|
61 |
80100 =
45Increase in the number of balloons
= 61 - 59
= 2
4 u = 2 + 18
4 u = 20
1 u = 20 ÷ 4 = 5
Number of red balloons at first
= 5 u
= 5 x 5
= 25
Number of black balloons at first
= 59 - 25
= 34
Answer(s): 34