Question

How many three digit numbers are divisible by both 3 and 4?

Answer 1

$three \: disit \: no. \: divisible \: by \: both \: 3 \: and \: 4 \: are \: \\ 108..120..124..........................996 \\ a = 108 \\ d = 12 \\ l = a + (n - 1)d \\ 996 = 108 + (n - 1)12 \\ 996 - 108 = 12n - 12 \\ 12n = 888 + 12 = 900 \\ n = \frac{900}{12} = 75$