2 There are 4 red n 4 blue hats In how many ways 4 hats can be selected so that

2*4c3*4c1+2*4c4=34
11 years agoHelpfull: Yes(11) No(1)
we have to select 4 hats so that there will be at least 3 red or 3 blue hats..so first we can choose all 4 hats are red,secondly all 4 hats are blue,thirdly 3 red & 1 blue hat and fourthly 3 blue & 1 red hat..
So total no f ways=1+1+1+1=4
11 years agoHelpfull: Yes(10) No(14)
2*4c3*4c1+2*4c4*4c0
11 years agoHelpfull: Yes(4) No(0)
for at-least 3 red hat: 4C3*4C1
for at-least 3 blue hat: 4C3*4C1
thus the reqd. selection is: 2(4C3*4C1)
= 2(4*4)
= 32
11 years agoHelpfull: Yes(1) No(3)
we can choose all 4 hats are red,secondly all 4 hats are blue,thirdly 3 red & 1 blue hat and fourthly 3 blue & 1 red hat.............
2*(4C4*4C0+4C3*4C1)
10 years agoHelpfull: Yes(1) No(0)
4c3*4c1 *2 =32
11 years agoHelpfull: Yes(0) No(4)

2.There are 4 red n 4 blue hats.In how many ways 4 hats can be selected so that there would be atleast 3red or 3blue hats?