solution:
no of means(N)=28
so,no of terms must be 30
m15 and m14 are middle one
common difference(d)=b-a/n+1
=b-a/29.................................(i)
m14=28
a+14d=59...............(iI)
m15=63
a+15d=63................(iIi)
(ii)-(i) then
d=4 put value of d in eqn (Ii)
a+15*4=63
or,a+60=63
or,a=63-60
a=3 ans
putting the value of d in eqn (i)
4=b-a/29
crooss multiply on both sides
b-a=116
or,b-3=116
0r,b=116+3
thus b=119 ans
here u go you