Question

Solution with explanation

Answer 1

Answer:

Here is your answer:)

Step-by-step explanation:

AP : 3, 7, 11, . . .

a = 3

d = a2 - a1

= 7 - 3

= 4

an = 144

n = ?

an = a + (n- 1) d

144 = 3 + (n-1)4

144-3 = (n-1)4

141 = ( n-1) 4

141/4 = (n-1)

35.25 = n - 1

35.25 + 1 = n

36.25 = n

n can't be in decimal

so 144 is not a term of the given AP.

Answer 2

Answer:

a=3

d=a2-a1=7-3

d=4

an=144

an=a+(n-1)d

144=3+(n-1)4

144-3=(n-1)4

141=(n-1)4

141=4n-4

141+4=4n

145/5=n

as n is in fraction therefore the term is not present in the ap as n cannot be a decimal ,fraction,-ve