In a bag, there are red and blue cubes in the ratio 4 : 7 I add 10 more red cubes to the bag. Now there are red and blue cubes in the ratio 6 : 7 How many blue cubes are in the bag?
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Answered by
13
Answer:
35 blue cubes
Step-by-step explanation:
The following is the most mechanical approach I can think of.
The current ratio is 4:7. So there are 4k red and 7k blue for some unknown number k.
When we add 10 red, we end up with 4k+10 red. The blues remain unchanged at 7k.
So the new proportion is (4k+10):7k. We are told that the proportion (4k+10):7k is 6:7. So
4k+107k=67.
If we multiply through by 7k, we get 4k+10=6k, and therefore k=5. It follows that there are 35 blues in the bag
Answered by
1
No. of red cubes= 5x+10 which is 6x
No. of blue cubes = 7x
5x+10+7x=6x+7x
12x+10=6x+7x
12x+10=13x
10=13x-12x
10=x
No. of blue cubes= 7x
=7×10
=70 cubes
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