Step-by-step explanation:
-3x - 4 < 2
-3x < 2 + 4
-3x < 6
x < 6/ - 3
x < - 2
Answer:
The correct answer has already been given (twice). I'd like to present two solutions that expand on (and explain more completely) the reasoning of the ones already given.
One is using the hypergeometric distribution, which is meant exactly for the type of problem you describe (sampling without replacement):
P(X=k)=(Kk)(N−Kn−k)(Nn)
where N is the total number of cards in the deck, K is the total number of ace cards in the deck, k is the number of ace cards you intend to select, and n is the number of cards overall that you intend to select.
P(X=2)=(42)(480)(522)
P(X=2)=61326=1221
In essence, this would give you the number of possible combinations of drawing two of the four ace cards in the deck (6, already enumerated by Ravish) over the number of possible combinations of drawing any two cards out of the 52 in the deck (1326). This is the way Ravish chose to solve the problem.
Another way is using simple probabilities and combinations:
P(X=2)=(4C1∗152)∗(3C1∗151)
P(X=2)=452∗351=1221
The chance of picking an ace for the first time (same as the chance of picking any card for the first time) is 1/52, multiplied by the number of ways you can pick one of the four aces in the deck, 4C1. This probability is multiplied by the probability of picking a card for the second time (1/51) times the number of ways to get one of the three remaining aces (3C1). This is the way Larry chose to solve the this.
Step-by-step explanation:
First, let's convert the givens to decimals to make calculations easier:
2 (3/4) = 2.75
9(5/8) = 9.625
We are given that:
Josie can hike 2.75 miles in one hour.
To know the time that Josie would take to hike 9.625 miles, we will simply do cross multiplication as follows:
2.75 miles ..........> 1 hour
9.625 miles .............> ?? hours
Time = (9.625*1) / (2.75) = 3.5 hours
Colfax:
Add the ratio numbers together:
5 + 4 = 9
Divide total students by that:
270 / 9 = 30
Multiply each ratio by 30:
Boys = 30 *5 = 150
Girls = 30 * 4 = 120
Do the same for Winthrop:
4 +5 = 9
180 /9 = 20
Boys = 20 * 4 = 80
Girls = 20 * 5 = 100
Total students = 270 + 180 = 450
Total Girls = 120 + 100 = 220
Fraction that are girls = 220 / 450 which reduces to 22/45
