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Question

Question

P6 Mathematics

Question post on Sun, 14/07/2019 8:27pm

hi! can help us with this qn part (b)? tq!

_________

The ratio of the number of balls in Box A to the number of balls in Box B was 5:6 at first. 2/5 of the balls in Box A and 5/18 of the balls in Box B were red. The rest of the balls were yellow.

(a) What was the ratio of the number of yellow balls in Box A to the number of red balls in Box B at first?

(b) Ali took out a total of 50 balls from both boxes. He then put them back into Box A and Box B such that the number of red balls in each box became the same. The number of yellow balls in each box also became the same. In the end, how many yellow balls were there in each box?

Answer

BigDevil · Answer 1 · Post on Tue, 16/07/2019 12:55am

	Box A	Box B	Total
Total Balls	15u	18u	33u
Red Balls	²/₅ × 15u = 6u	⁵/₁₈ × 18u = 5u	11u
Yellow Balls	15u – 6u = 9u	18u – 5u = 13u	22u

In the end
Red Balls	5.5u	5.5u	11u
Yellow Balls	11u	11u	22u

(a)

Ratio of Yellow Balls (A) to Red Balls (B) -> 9 : 5

(b)

Ali took (6u – 5.5u) = 0.5u red balls from A to put into B

He took (13u – 11u) = 2u yellow balls from B to put into A

2.5u = 50

1u = 20

11u = 220

Each box had 220 yellow balls in the end

MrsMarcus · Answer 2 · Post on Tue, 16/07/2019 5:32am

MrsMarcus Post on Tue, 16/07/2019 5:32am

tq for your help!

BigDevil · Answer 3 · Post on Tue, 16/07/2019 9:05pm

BigDevil Post on Tue, 16/07/2019 9:05pm

You are most welcome 🙂

alfretztay · Answer 4 · Post on Mon, 22/07/2019 10:13am

(a)
5 : 6
15 : 18
(2/5) x 15 = 6
15 – 6 = 9
At first —
Box A : 15 units
red : 6 units
yellow : 9 units
Box B : 18 units
red : 5 units
yellow : 18 – 5 = 13 units
yellow balls in Box A : red balls in Box B is 9 : 5

(b)
red : 6 + 5 = 11 units
11/2 = 5.5
6 – 5.5 = 0.5
yellow : 9 + 13 = 22 units
22/2 = 11
13 – 11 = 2
2 + 0.5 = 2.5
2.5 units = 50
1 unit = 20
22/2 = 11
11 units = 11 x 20 = 220

Ans : (a) 9 : 5; (b) 220 yellow balls.

cfschan · Answer 5 · Post on Mon, 28/12/2020 5:00pm

Is it possible to read the question slightly differently ie as in taking out 50 balls (1 unit of red and 4 units of yellow) ie 5 units = 50 balls, therefore 1 unit = 10 balls. This is the effective difference between contents in Box A and Box B.

After that, we would reassign 5 red balls to Box A and Box B each, and reassign the 4 units of yellow balls from B and return 2 units (20 balls each) to both A and B respectively?

Hence there would be an equal number of 55red and 110yellow balls in each of box A and B.
Thanks for your views.