Answer:
10
The 3rd option , C.
Answer:
24 blue cars
Step-by-step explanation:
Set up a proportion to solve this...
40/5 = x/3 (forty red cars is to five red cars as 'x' number of blue cars is to 3 blue cars)
Now solve by cross multiplying...
120 = 5x
24 = x
Answer:
1/1560
Step-by-step explanation:
The chance of you winning is 1/40, since there are 40 students and you are one of those students. Since, you cannot win again once you win once, you are eliminated. This leaves us with 39 people left. The chances of your friend being chosen out of the 39 people left is 1/39. Now you must multiply 1/40 and 1/39. After multiplying, you get 1/1560.
first subtract the last equation from the first. this gives:-
-x + y = -8 .....................(1)
Then multiply the first equation by 2 and add it to the 2nd equations This gives
9x = 18
so x = 2
and from equation (1) y = -8 + 2 = -6
Substituting for x and y in the second equation
z = (24 -5(2) -12) / 2 = 1
Answer is choice b.