Question

 A bag contains 7 black and 8 red balls determine the number of ways in which 3 black and 4 red balls can be selected​

Answer 1

Answer:

Step-by-step explanation:

There are 5 black and 6 red balls in the bag.

2 black balls can be selected out of 5 black ball in  

5

C  

2

​  

 ways and 3 red ball can be selected out of 6 red balls in  

6

C  

3

​  

 ways.

Thus, by multiplication principle, required number of ways of selecting 2 black and 3 red balls is    

5

C  

2

​  

×  

6

C  

3

​  

 

=  

2!3!

5!

​  

×  

3!3!

6!

​  

 

=  

2

5×4

​  

×  

3×2×1

6×5×4

​  

=10×20=200

Answer 2

Step-by-step explanation:

no. of ways in which 3black are selected from 7black is 7c3

no. of ways in which 4 red are selected from 8red is

8c4

total no. of ways = 7c3×8c4 = 7×6×5×8×7×6×5=362800

I hope this helps