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 An envelope is selected at random and a card is withdrawn and found to be red.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:
The second one is the best answer to your question
Answer:
The rate is 609 kilometers per 7 hours.
The unit rate is 609/7 = 87 kilometers per hour.
Step-by-step explanation:
Should be right
Answer:
Step-by-step explanation:
378,903,970.