Question

In an AP is a = 10, d=3 then it's 8th term is _____​

Answer 1

Given

we have given first term (a)= 10

common difference (d)= 3

To Find

We have to find 8th term

$\sf\huge {\underline{\underline{{Solution}}}}$

Since , first term is 10

and common difference is 3

8th term can also be written as : a+ (8-1)d

an= a+(n-1)d

8th term = a+7d

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$ = 10+7(3)

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$ = 10+21

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$ = 31

∴ 8th term is 31

We can also find other terms :

second term => a+d= 10+3= 13

third term= a+2d= 10+6= 16

fourth term => a+3d= 10+9= 19

fifth term=>a+4d= 10+12=22

sixth term => a+5d= 10+15=25

seventh term=> a+6d= 10+18=28

Thus,our AP is : 10,13,16,19,22,25,28,31..

More information=>

For finding sum of n terms we use formula:

• Sum= n/2[2a+(n-1)d]

If last term is given and have to find sum:

• Sum= n/2(a+l)

Answer 2

8th term = a+7d

= 10+7(3)

= 10+21

= 31

∴ 8th term is 31

In an AP is a = 10, d=3 then it's 8th term is 31