Question

If 4,a,b,28 are in ap the the value of b is

Answer 1

Answer:

b=20

Step-by-step explanation:

4,a,b,28 in ap

t1=4, t2=a, t3=b, t4=28

a=4, d=a-4=b-a=28-b,

tn=a+(n-1)d

when n=4

t4=4+(4-1)(28-b)

28=4+3(28-b)

28-4=84-3b

24=84-3b

3b=84-24

3b=60

b=60/3

b=20