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 An envelope is selected at random and a card is withdrawn and found to be red.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:23
Step-by-step explanation:
Hey there!
2x + 7 = 27
2x = 20
x = 10
3x + 1 = 28
3x = 27
x = 9
The values for both of these equations are 9 and 10; therefore, the answers are not equivalent.
I hope this helps!
Answer:
250 nickles
Step-by-step explanation:
Nickles and dimes are coins with different currency values. One nickel(N) is equal to 5 cents while one dime(D) is equal to 10 cents. The ratio of nickel:dime is 5:7, to put into the equation it will be:
N/D= 5/7
7N=5D ---> 1st equation
There are 350 dimes, the equation will be:
D=350 ----> 2nd equation
We can find out the number of nickels by substitute the 2nd equation into the first. The calculation will be
7N=5D
N= 5D/7
N=5(350)/7
N= 250
Answer:
8x
15
y
9
Step-by-step explanation: