Question

If 2a+b=7 and b+2c=23, what is the average of a, b, and c?
a)5 b)7.5 c)15 d)12.25

Answer 1

See, 2a + b=7..............(i)
b+ 2c =23.....................(ii)
Adding (i) and (ii)-
2a + 2b +2c =30
2(a+b+c) =30
a+b+c=15
Therefore average =a+b+c/3
=15/3= 5
Hope, this helps!

Answer 2

Answer:

Option A, 5

Step-by-step explanation:

If 2a + b = 7 and b + 2c = 23

Then we have to find the average of  a, b and c.

In other words we have to find the value of $\frac{a+b+c}{3}$

By adding both the equations

(2a + b) + (b + 2c) = 7 + 23

2a + 2b + 2c = 30

2(a + b + c) = 30

(a + b + c) = $\frac{30}{2}$ = 15

⇒$\frac{(a+b+c)}{3}=\frac{15}{3}=5$

Therefore, average of a, b and c is 5

Option A, 5 is the answer.