Is 68 a term of the A.P ? 7,10,13...........
Let 's assume 68 is a term
an = 68
a = 7
d = 10 - 7 = 3
an = a + (n - 1) d
68 = 7 + (n - 1) 3
61 = (n - 1) 3
n - 1 = 20.33
n = 21.33
Since n is not a whole number and the number of terms cannot be in decimals, 68 is not a term of the AP 7 , 10, 13....