Question

which term of the A.P 3;15;27;39... will be 120 more than its 21st term​

Answer 1

Step-by-step explanation:

a=3

d=15-3=12, n=21

to find 21st term.

nth term =a+(n-1) d

3+(21-1)12

=3+20(12)

=3+360

=363

was the 21st term.

Answer 2

Step-by-step explanation:

here a=3 and d=(15-3)=12

21st term is given by

a+20d it is a formula

=3+20 (12)

=3+240

=243