Aptitude - Problems on Numbers - Discussion

Discussion Forum : Problems on Numbers - General Questions (Q.No. 12)
12.
The product of two numbers is 120 and the sum of their squares is 289. The sum of the number is:
20
23
169
None of these
Answer: Option
Explanation:

Let the numbers be x and y.

Then, xy = 120 and x2 + y2 = 289.

(x + y)2 = x2 + y2 + 2xy = 289 + (2 x 120) = 529

x + y = 529 = 23.

Discussion:
12 comments Page 2 of 2.

Ugyen Jigme Chogyel said:   4 months ago
The product of two numbers is 120.
x + y = 120 and x^2 +y^2 = 289.
Lets take 120/15 = 8, or 15 * 8 = 120.
15^2 + 8^2 = 225 + 64.
= 289.
So, the sum of the number is:
15 + 8 = 23(the answer)
Hope it helped:)
(1)

Argghx said:   2 months ago
A^2+b^2=289 a*b=120apply (a+b) ^2 formula and replace the value.

If you are thinking square rooting 289 and getting a+b = 17 is right,

Here it doesn't satisfy thee first case of a*b=120.


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