Question

If the first term of an AP is 10, the last term is 50 and the sum of the terms is 300, then the number of terms are...?​

Answer 1

Answer:

number of terms are 10

Step-by-step explanation:

Here

first term is 10 =a

Last term is 50=l

sum of all terms us 300=an

number of terms=?

We know

sn=n/2(a+l)

300=n/2(10+50)

300*2=n(60)

600=60n

n=600/60

n=10

therefore number of terms in the given ap is 10