A box contains 4 red, 3 white and 2 blue balls. Three balls are drawn at random. Find out the number of ways of selecting the balls of different colours?

62

48

12

24

Correct Answer : D

The 288^{th} term of the series a, b, b, c, c, c, d, d, d, d, e, e, e, e, e, f, f, f, f, f, f…. is

126, 756, 252, 1512, ____

In a number system the product of 44 and 11 is 2124. The number 3111 of this system, when converted to the decimal number system,

becomes: