Is 68 a term of the A P 7,10,13 - Maths - Arithmetic Progressions

Question

Is 68 a term of the A P ? 7,10,13

Rosy · Accepted Answer

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

Is 68 a term of the A.P ? 7,10,13...........