Question

5. Find the number of terms in each of
the following APs :
i) 7, 13, 19, ...,205
ii) 18, 15 1/2, 13,...,—47​

Answer 1

Answer:

i) a=7, d=13-7=6, An=205

An=a+(n-1)d

205=7+(n-1)6

205=7+6n-6

205=7-6+6n

205=1+6n

6n=205-1

6n=204

n=204/6

n=34

The no. of terms are 34.