How many multiples of 4 lie between 10 and 250?

The multiples of 4 lie between 10 & 250 is

12, 16, 20,.....248

So, first term (a) = 12

Since it is multiples if 4 the common difference will be 4

a_n = 248

a_n = a + (n-1) d

248 = 12 + (n-1) 4

236 = 4(n-1)

59 = n-1

n = 60.