Question

I. Four al
its alphabet:
1. If an AP, if a3 = 13 and a=5, then its common difference is
a) 8
b)-4
d) 2
c) 4​

Answer 1

Step-by-step explanation:

a=5

a3=13

common difference =a2-a1

then

a2-a1=a3-a2

a2-5=13-a2

a2+a2=13+5

2a2=18

a2=9

now,

d = 9-5

=4

Answer 2

Step-by-step explanation:

Anwser =8

an=a + (n-1)d

13=5 + (2-1)d

13=5+d

13-5=d

d=8