Question

3. There were 120 counters in a box. The numbers of red, blue and green counters were in the ratio 5: 2:3 respectively. Fiona put another 45 counters into the box As a result, the number of red counters was increased by 20% and the number of blue counters was increased by 25%. (a) How many green counters were there in the box at first? (b) By what percentage was the number of green counters increased?​

Answer 1

a) There were 36 green counters in the box in the beginning.

b) The green counters increased by 75%

Explanation:

Red: 5

Blue: 2

Green: 3

Total: 10

Red 5/10 x 120 = 60

Blue: 2/10 x 120 = 24

Green 3/10 x 120 = 36

45 more counters were added. The total counters is now 165.

Red increased by 20%

60 + .2(60) = 72

Blue increased by 25%

24 + .25(24) = 30

Greens: 165 - 72 - 30 = 63

The greens were 36 and they increases to 63

`(63 - 36)/(36)` = .75 and .75 as a percentage is 75%