The sum of two numbers is 40 and their difference is The ratio of the numbers is:  

A    11:9

B    11:18

C    21:19

D    22:9

Solution

Correct Answer: Option A

 

Let x and y denote the two numbers and, without a loss of generality, let x > y. 

Since the sum of the numbers is x + y

and

the difference is x - y,

we see that we have the system:  x + y = 40 and

x - y = 4. 

By adding these two equations:  (x + y) + (x - y) = 40 + 4  ==> 2x = 44  ==> x = 22. 

Then, since x + y = 40 implies y = 40 - x:  y = 40 - x = 40 - 22 = 18. 

Therefore, the two numbers are 22 and 18. so the ratio =22:18=11:9

 

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