Answer:
66.67% probability of selecting a black marble from the bag.
Step-by-step explanation:
Initially there are 16 marbles, 10 of which are black and 6 of which are red.
A red marble is drawn and not put back. So now there are 15 marbles, of which 10 are black.
So there is a 10/15 = 2/3 = 0.666% 7 = 66.67% probability of selecting a black marble from the bag.
Answer:
-1/4
Step-by-step explanation:
2-1 over -3-1 = 1/-4
Answer:
10 pounds.
Step-by-step explanation:
Let x pounds be the amount of mixed nuts we require.
Amount of peanuts in this mix = 0.70x pounds. Amount of peanuts in the 20% mix = 0.20*15 = 3 pounds.
So we have the equation:-
0.70 x + 3 = 0.40(x + 15)
0.70 x + 3 = 0.40(x + 15)
0.70x + 3 = 0.40x + 6
0.70x - 0.40x = 6 - 3
0.30x = 3
x = 10.
Answer:
8.0x
Step-by-step explanation:
Answer:
4:1
Step-by-step explanation:
x+20 : y+20 = 5 : 2
(x+20)/(y+20) = 5/2
2(x+20) = 5(y+20)
2x+40 = 5y+100
2x = 5y+60 (1)
x-5 : y-5 = 5:1
(x-5)/(y-5) = 5/1
x-5 = 5(y-5)
x-5 = 5y-25
x = 5y-20 (2)
Solve (1) & (2) simultaneously,
2(5y-20) = 5y+60
10y-40 = 5y+60
5y = 100
y = 20
x = 5y-20
x = 5(20)-20 = 100-20
x = 80
x:y
80:20
4:1
