Answer:

Step-by-step explanation:
3 envelopes having 2 red card
2 envelopes having 1 red card and 1 black card
1 envelope having 2 black cards
We are given that . An envelope is selected at random and a card is withdrawn and found to be red.
So, No. of ways of envelope having red card = 3+2 = 5
No. of required ways of envelope having 1 red card and 1 black card = 2
So, probability of getting an envelope having 1 red card and 1 black card = 
Hence The chance the other card is black is 
Answer what? This question? Oh, I'm answering it right now. Did you have another question out? Well, I can't see it.
Answer:
401.92u^3
Step-by-step explanation:
Volume for a cylinder=(pi*r^2)*h because it is the area of the circle times the height of the cylinder so,
(3.14*4^2)*8=401.92
25 metres. Because 1/10th of a kilometre is a 100 metres. And four athletes divided by 100 metres is 25 metres.