Question

If in an A-P, a=15,d=-3, an=o find the value of n​

Answer 1

Given :-

First term (a) = 15

Common difference (d) = -3

Last term (an) = 0

To Find :-

Number of terms n

Solution :-

Putting values

0 = 15 + (n - 1)-3

-15 = -3n + 3

-15 - 3 = -3n

-18 = -3n

-18/-3 = n

6 = n