There are 200 balls in a box. 0.3 of them are pink balls, and the rest are black and red balls. If there are 14 as many black balls as red balls. How many red balls are there?
| Pink balls |
Black balls |
Red balls |
Total |
| 3 u |
7 u |
10 u |
| |
1 p |
4 p |
|
0.3 =
310 =
310 Fraction of balls that are black and red balls
= 1 -
310 =
710 Total number of balls = 10 u
10 u = 200
1 u = 200 ÷ 10 = 20
Number of black balls and red balls
= 7 u
= 7 x 20
= 140
Number of black and red balls
= 1 p + 4 p
= 5 p
5 p = 140
1 p = 140 ÷ 5 = 28
Number of red balls
= 4 p
= 4 x 28
= 112
Answer(s): 112
