Answer:
It is the third option: (10C1) (20C1( / 50C2.
Step-by-step explanation:
The number of ways of selecting 2 marbles = the number of combination of any 2 marbles in the 50 marbles in the bag and this is 50C2. It is combinations because the order of drawing the marbles does not matter.
The number of combinations of one being red and the other blue = 10C1 times 20C1.
So the answer is (10C1) (20C1( / 50C2.
1/9 - 5/6
Convert both of them into denominators of 18.
2/18 - 15/18
Subtract the numerators and keep the denominator:
-13/18
Answer:
Step-by-step explanation:
Area = 42x + 56
length * width = 14* 3x + 14*4
14 * width = 14*(3x+4)

Answer:
Carrie and Joan have 80 nickels and 40 dimes, respectively, and each one has an amount of money of 4 US dollars.
Step-by-step explanation:
Let be
and
the amounts of nickels and dimes that Carrie and Joan have, as
the total amount of money that both Carrie and Joan have. A nickel is a five cent coin and a dime is a ten cent coin.
The following equations are constructed after a careful reading on statement:
Carrie's amount of money:
(Eq. 1)
Joan's amount of money:
(Eq. 2)
Relation between amounts of coins:
(Eq. 3)
First we eliminate
by equalizing (Eq. 1) and (Eq. 2):

Then, we reduce the resulting formula by (Eq. 3):



And rest of variable are now determined:




Carrie and Joan have 80 nickels and 40 dimes, respectively, and each one has an amount of money of 4 US dollars.
First of all, we have to observe this triangles separated by the height. These small and big triangles are similar according to the Angle-Angle-Angle principle.
a. We can find all of these length using the cosine of the angle, Pythagoras theorem and the principle of the similarity of triangles.
b. According to the cosine of the angle we can write that, cosθ = 12/a = 5/13 and from here a = 31.2. After finding that using Pythagoras theorem, we can write that
. According to the similarity of the triangles, we can write that 31.2/d = 28.8/12 and d = 13. Applying Pythagoras theorem we find that c = 5.
c. We already gave the answer for this question in part b