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.

Sunil said:   2 decades ago
The questions is for sum of two consecutive "even numbers"
So in your answer if x=1 then x+2=3 Both are odd numbers.

Therefore i think the solution may be as follows:-
Let the numbers be "2x" and "2x + 2".

Then, (2x + 2)^2 - 2x^2 = 84
8x+4=84
x=10.
The required sum = 2x + (2x + 2) = 42.


Post your comments here:

Your comments will be displayed after verification.