Which term of the A.P. 3, 8, 13,… is 248 ?

Given A.P is 3, 8, 13,…


Here, a1 = a = 3, a2 = 8


Common difference, d = a2 – a1 = 8 – 3 = 5


We know, an = a + (n – 1)d where a is first term or a1 and d is common difference


an = 3 + (n – 1)5


an = 3 + 5n – 5


an = 5n – 2


Now, to find which term of A.P is 248


Put an = 248


5n – 2 = 248


5n = 248 + 2


5n = 250



n = 50


Hence, 50th term of given A.P is 248


3