SSC CHSL Model Paper 2

Question : 61 of 100

Marks: +1, -0

The sum of the squares of three numbers is 138, while the sum of their products taken two at a time is 131. Their sum is:

Solution:

Let the numbers be a, b and c.
Then,

a^2 + b^2 + c^2 = 138

and ab + bc + ca = 131

(a + b + c)^2 = a^2 + b^2 + c^2

+ 2(ab + bc + ca)

138 + 2 × 131 = 400

⇒ (a + b + c) = 400 = 20

Go to Question:

Prev Question

Next Question