Q. The number of group that can be made from5 different green balls, 4 different blue balls and 3 different red balls, if at latest 1 green and 1 blue ball is to be included, is
A) 3700
B) 3720
C) 4340
D) None of these
Explanation
(b)
At least one green ball can be selected out of 5 green balls in $2^{5} - 1 = 31\$ways. Similarly at least one blue ball can be selected from 4 blue balls in $2^{4} - 1 = 15$ ways and at least one red or not red can be select in $2^{3} = 8$ ways
Hence ,required number of ways $= 31 \times 15 \times 8 = 3720$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.