#1**+1 **

4. Don't know the answer here, NSS

5. Probability = area of smaller circle / area of larger circle =

pi * (3)^2 / [ pi * (12)^2 ] = 9 / 144 = 1 / 16

CPhill Apr 10, 2018

#2**+2 **

4.

The number of ways that you can have 5 cards where three are 4s and the other two are not 4 is

4C3*48C2 = 4*1128= 4512

The number of ways you can choose 5 cards from 52 cards is 52C5 = 2598960

so the prob you want is 4512/2598960 =

factor(4512) = 2^5*3*47

factor(2598960) = 2^4*3*5*7^2*13*17

\(\dfrac{4512}{2598960} = \dfrac{2*47}{5*49*13*17}=\dfrac{94}{54145}\)

.Melody Apr 10, 2018