Question

Average of 80 numbers are 42. When 5 more numbers are included the average of 85 numbers become 45. Find the average of 5 numbers. 82 89 93 98

Answer 1

Let the 80 no.s be p,q,r,s.............

Then there avg

P+q+r+s+.........(80 no.s)/80=42

Then ,p+q+r+s+........=42*80=3360.........(1)

Let the five no.s added be a,b,c,d,and e

Then p+q+r+s+.........+a+b+c+d+e(85no.s)/85=45

Then p+q+r+s+......+a+b+c+d+e=45*85=3825.......(2)

Therefore,a+b+c+d+e=(2)-(1)=3825-3360=465

Then avg of a,b,c,d,e

=>(a+b+c+d+e)/5=>465/5

=>93