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 An envelope is selected at random and a card is withdrawn and found to be red.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:
good luck...
Step-by-step explanation:
(12+8)\ 5 + 15=19... this solution works because 12+8=20.. 20/5=4 and then 4+15=19