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The ratio of two number is 4:9.When 5 is subtracted from each of them,the new ratio becomes 3:8. Find the numbers.

User Jan Wy
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1 Answer

4 votes

Answer:

The numbers are 20 and 45

Explanation:

Let the two numbers be a and b

The ratio of the two is 4:9

That means;

a/b = 4/9

9a = 4b •••••(i)

secondly;

Subtracting 5 from each gives a ratio of 3:8

(a-5)/(b-5) = 3/8

8(a-5) = 3(b-5)

8a - 40 = 3b - 15

3b - 15 + 40 = 8a

3b + 25 = 8a

a = (3b + 25)/8 •••(ii)

Insert this into 1

9(3b + 25)/8 = 4b

27b + 225 = 32b

32b - 27b = 225

5b = 225

b = 225/5

b = 45

From i;

9a = 4b

9a = 4 * 45

a = 4 * 45/9

a = 20

User Roger Ray
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