40% of the people are performers for a concert and the rest are spectators. 80% of the spectators are parents and there are 630 more parent spectators than child spectators. How many parent spectators must leave so that 35% of the people are parent spectators?
|
Performers |
Spectators |
|
2x5 |
3x5 |
|
|
Children |
Parents |
|
|
1x3 |
4x3 |
Before |
10 u |
3 u |
12 u |
Change |
|
|
- ? |
After |
13x1 = 13 u |
7x1 = 7 u |
40% =
40100 =
25 80% =
80100 =
45 35% =
35100 =
720The 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 more parent spectators than child spectators at first
= 12 u - 3 u
= 9 u
9 u = 630
1 u = 630 ÷ 9 = 70
If some parent spectators leave, the total number of child spectators and performers remains unchanged.
Number of parent spectators who must leave so that 35% of the people are parent spectators
= 12 u - 7 u
= 5 u
= 5 x 70
= 350
Answer(s): 350