40% of the people are performers for a concert and the rest are spectators. 60% of the spectators are children and there are 180 less parent spectators than child spectators. How many child spectators must join so that 68% of the people are child spectators?
|
Performers |
Spectators |
|
2x5 |
3x5 |
|
|
Parents |
Children |
|
|
2x3 |
3x3 |
Before |
10 u |
6 u |
9 u |
Change |
|
|
+ ? |
After |
8x2 = 16 u |
17x2 = 34 u |
40% =
40100 =
25 60% =
60100 =
35 68% =
68100 =
1725The total number of spectators at first is repeated. Make the total number of spectators the same. LCM of 3 and 5 is 15.
Number of less parent spectators than child spectators at first
= 9 u - 6 u
= 3 u
3 u = 180
1 u = 180 ÷ 3 = 60
If some child spectators join, the total number of parent spectators and performers remains unchanged.
Number of child spectators who must join so that 68% of the people are child spectators
= 34 u - 9 u
= 25 u
= 25 x 60
= 1500
Answer(s): 1500