Question

Find 4th term of ap 1,4,7

Answer 1

the formula for finding the term of an a.p is= an=a+(n-1)d

So..,here a which is first term is 1
and the difference is 3
and the term to find is 4.
Now,putting tha values in the formula
a4=1+(4-1)3
=1+3×3=10--ans

Answer 2

a=1
d=$a _{2} - a _{1} \\ 4 - 1 = 3$
a+(4-1)d=1+[(4-1)×3]
=1+[3×3]=1+9=10