SSC CHSL 2019 PYQ — Question 65

SSC CHSL - 1st July 2019 - Shift 3 • Quantitative Aptitude • Q65

There are three numbers. If the average of any two of them is added to the third number, the sums obtained are 177, 163 and 138. What is the average of the largest and the smallest of the given numbers?

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. 76

Understanding

Application

Let numbers are a, b and c:

Given

(a + b)/2 + c = 177

(b + c)/2 + a = 163

(a + c)/2 + b = 138

 

Given equations can be converted as:

a + b + 2c = 354 ---- (1)

b + c + 2a = 326 ---- (2)

c + a + 2b = 276 ---- (3)

Adding all equations:

⇒ 4(a + b + c) = 956

⇒ (a + b + c) = 956/4 = 239

From equation 1, 2 and 3:

c = 354 – 239 = 115

a = 326 – 239 = 87

b = 276 – 239 = 37

Average of the largest and the smallest of the given numbers

= (115 + 37)/2

= 76