Question

which term of the AP 3, 10 ,17 ,... . will be 84 more than its 13th term

Answer 1

Heya !!!


AP = 3 , 10 , 17 ........



Here,



first term (A) = 3


Common difference (D) = 7



Therefore,

13th term is given by

T13 = A + 12D => 3 + 12 × 7 = 3 + 84 = 87



Required term = ( 87 + 84) = 171


Therefore,

Tn = A + (N-1) × D


171 = 3 + (N-1) × 7


171 = 3 + 7N -7


171 = 7N-4


7N = 171 +4


7N = 175


N = 175/7

N = 25

Hence,


25th term will be 84 more than it's 13th term.




HOPE IT WILL HELP YOU....... :-)

Answer 2

a+(n-1)d=84+a+(13-1)d
(n-1)7=84+(13-1)7
(n-1)7=84+84
7n-7=168
7n=175
n=25