PSLEAt first, Leah had a total of 50 black and red balloons. 19 red balloons burst. She then increased the number of black balloons by 80%. After that, Leah had a total of 47 balloons. How many red balloons did she have at first?
|
Black |
Red |
Total |
Before |
5 u |
|
50 |
Change |
+ 4 u |
- 19 |
- 3 |
After |
9 u |
|
47 |
80100 =
45Decrease in the number of balloons
= 50 - 47
= 3
4 u = 19 - 3
4 u = 16
1 u = 16 ÷ 4 = 4
Number of black balloons at first
= 5 u
= 5 x 4
= 20
Number of red balloons at first
= 50 - 20
= 30
Answer(s): 30