PSLEAt first, Leah had a total of 50 black and white balloons. 13 white balloons burst. She then increased the number of black balloons by 70%. After that, Leah had a total of 51 balloons. How many white balloons did she have at first?
|
Black |
White |
Total |
Before |
10 u |
|
50 |
Change |
+ 7 u |
- 13 |
+ 1 |
After |
17 u |
|
51 |
70100 =
710Increase in the number of balloons
= 51 - 50
= 1
7 u = 1 + 13
7 u = 14
1 u = 14 ÷ 7 = 2
Number of black balloons at first
= 10 u
= 10 x 2
= 20
Number of white balloons at first
= 50 - 20
= 30
Answer(s): 30