TS EAMCET 2017 Code A Solved Paper

The number of ways to draw three balls from 12 are,
12C3=‌‌

12×11×10

3×2×1

=220
The number of ways to draw thee balls of same colour are,
5C3+3C3+4C3=10+1+4=15
The probability that the balls are not of same colour is calculated as,
P=1-Probability of same colour
=1−‌‌

15

220

=‌‌

41

44