25% of the people are performers for a concert and the rest are spectators. 80% of the spectators are children and there are 810 less parent spectators than child spectators. How many child spectators must join so that 92% of the people are child spectators?
|
Performers |
Spectators |
|
1x5 |
3x5 |
|
|
Parents |
Children |
|
|
1x3 |
4x3 |
Before |
5 u |
3 u |
12 u |
Change |
|
|
+ ? |
After |
2x4 = 8 u |
23x4 = 92 u |
25% =
25100 =
14 80% =
80100 =
45 92% =
92100 =
2325The 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
= 12 u - 3 u
= 9 u
9 u = 810
1 u = 810 ÷ 9 = 90
If some child spectators join, the total number of parent spectators and performers remains unchanged.
Number of child spectators who must join so that 92% of the people are child spectators
= 92 u - 12 u
= 80 u
= 80 x 90
= 7200
Answer(s): 7200