Question

find the 60th term of the AP 8,10,12,.......... if it has a total 60 terms and hence find the sum of it's last terms.​

Answer 1

Answer:

a=8 d=2 n=60 tn=? Sn=?

tn=a+(n-1)d

t60 =8+(60-1)2

= 8+118

=126

Sn=n/2[t1+tn]

= 60/2[8+126]

=30×134

=4020

Answer 2

Answer:

60th term = 126, Sum of 60 terms = 3720

Explanation:

First term = a

Common difference = d

Number of terms = n

To find 60th term of an A.P

Term(n) = a + (n - 1)d

             = 8 + (60 - 1) * 2

             = 8 + (59 * 2)

             = 8 + 118

Term(60)      =>  126

Sum of 60 terms is

Sum(n) = n/2 * (2a + (n - 1) d)

           =  60/2 ( 2(8) * (60 - 1) * 2)

           =   30 * (16 + 59(2) )

           =   30 * (16 + 118)

           =   30 * (134)

Sum(60)    => 3720

Hope it helps

Have a great day ;)