Question

Find the number of terms in each of the following APs :
a) 7,13,19,..., 205
b) 18,31/2,13,....,-47
guys please ans fast and do step by step​

Answer 1

a.

7,13,19

a=7, d=6, l=205

=> l=a+(n-1)d

205=7+6n-6

n=204/6= 34 terms.

b.

18,31/2,13,-47

a=18, d=-2.5, l=-47

=> l=a+(n-1)d

-47=18-2.5n+2.5

-47=20.5-2.5n

=>47+20.5 = 2.5n

=> n = 67.5/2.5 = 65 terms.

PLEASE MARK AS BRAINLIEST.....!!!!!!

Answer 2

Answer:

a) a=7. D=13-7=6. an=205.

an=a+(n-1)(D)

205=7+(n-1)(6)

205-7=(n-1)(6)

198=(n-1)(6)

(n-1)=198/6

(n-1)=33

n=33+1

n=34