Question

If 3,a,b,15 is an Ap ,then value of a +b is

Answer 1

Answer:

3,a,b,15 are in a.p

so, their common difference must be same.

so, a-3=b-a=15-b.

considering first and last terms!!

a-3=15-b.

sending 'b' to lhs and '3' to rhs!

therefore, a+b=15+3=18.

Answer 2

3 is term1
a is term2
b is term3
15 is term4
In an Ap term2-term1=term3-term2=term4-term3=...................term n -term n-1


15-b=a-3
15+3=a+b
a+b=18