Aptitude - Problems on Numbers - Discussion

Discussion Forum : Problems on Numbers - General Questions (Q.No. 15)
15.
What is the sum of two consecutive even numbers, the difference of whose squares is 84?
34
38
42
46
Answer: Option
Explanation:

Let the numbers be x and x + 2.

Then, (x + 2)2 - x2 = 84

4x + 4 = 84

4x = 80

x = 20.

The required sum = x + (x + 2) = 2x + 2 = 42.

Discussion:
21 comments Page 3 of 3.

Pratheep MSAJCE IT said:   1 decade ago
The difference of the squares of the number is 84

So (a^2)-(b^2)=84

then (a+b)(a-b)=84

(a-b)=2[it is difference between consecutive even no]

then (a+b)*(2)=84

A+B=42


Post your comments here:

Your comments will be displayed after verification.