Answer:
Step-by-step explanation:
The expected value is the probability of an event multiplied by the number of times the event happens. And if there is more than 1 event, the expected value is the sum of those.
There are 52 cards in a deck.
There are 12 face cards in a deck. (gain 10)
There are 4 ace in a deck. (gain 20)
Any other card is 36 of them. (lose 5)
The probability of face card is 12/52
The probability of ace is 4/52
The probability of any other card is 36/52
Thus the expected values is:
(12/52)(10) + (4/52)(20) + (36/52)(-5) = $0.38
For this problem you have yo set up two equations.
White shirts = w Yellow shirts = y
1st: w + y = 21
2nd: 9.95w + 11.50y = 235.30
Now we're going to do system of equations using substitution.
If w + y = 21, then y = 21 - w
If y = 21 - w, then you can substitute this in the second equation for y.
9.95w + 11.50(21 - w) = 235.30
9.95w + 241.5 - 11.50w = 235.30
-1.55w + 241.5 = 235.30
-1.55w = -6.2
w = 4, so 4 whites shirt were sold.
Now I'm finding out how many yellow shirts were sold using one of the two equations at the top.
w + y = 21
4 + y = 21
y = 17
So 17 yellow shirts were sold and 4 white shirts were sold.
Answer:
distance covered in 2 hours = 80 km
distance covered in 1 hour = 80÷2 = 40 km
distance covered in 7/2 hours = 40 × 7/2
= 140 km
(3 1/2hours = 7/2 hours)
Answer:
m = 2, n = - 3
Step-by-step explanation:
Given the 2 equations
2m + 3n = - 5 → (1)
5m + 3n = 1 → (2)
Subtract (2) from (1) term by term to eliminate n
2m - 5m = - 5 - 1
- 3m = - 6 ( divide both sides by - 3 )
m = 2
Substitute m = 2 into either of the 2 equations and solve for n
Substituting into (1)
2(2) + 3n = - 5
4 + 3n = - 5 ( subtract 4 from both sides )
3n = - 9 ( divide both sides by 3 )
n = - 3
