Question

Which term of the AP 3, 8, 13, 18 ... .s 78?​

Answer 1

Explanation:

a = 3

d = 5 (common difference)

an = 78

According to formula,

an= a+ (n-1)d

78= 3+(n-1)5

78-3=5n-5

75-+5 = 5n

80= 5n

n= 80/5

n= 16

Therefore, 16th term of AP is 78.

Hope it helps you!!!

Answer 2

78=3+(n-1)5

78-3=(n-1)5

75=(n-1)5

75/5=n-1

15=n-1

15+1=n

n=16