Question

The average monthly income of a and b is rs.7760. the average monthly income of b and c is rs 10990 and that of c and a is rs 9070. what is the annual income of b?

Answer 1

a+b=7760×2
b+c=10990×2
c+a=9070×2
2(a+b+c)=2(7760+10990+9070)
a+b+c=2780
b=2780-18140=9680
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Answer 2

Answer:

116160

Step-by-step explanation:

Monthly income of -

A+B = 2 × 7760 = 15520 ---1

B+C = 2 × 10990 = 21980 ---2

C+ A = 2 × 9070 = 18140 --- 3

Adding all the three equations -

2(A+B+C) = 15520+21980+18140

2(A+B+C) = 55460

A+B+C = 55460/2

A+B+C = 27820

Thus, from equation 3 -

B = 27280 - 18140

B = 9680

Therefore, B's annual salary = 12 × 9680

= 116160

Thus the annual income of b is = Rs. 116160