This is impossible to answer. This all depends on what you define as a 'person.' If you are talking about the first Homo Sapiens, then that would be around 2 million years ago, but the predecessors of Homo sapiens could also be considered 'people,' so then you'd have to determine at what point they came into existence.
Given that the number rolled is less than 3,
we know that it must be either a 1 or a 2 .
The probability of it being a 4 is <em>zero</em>.
3) subtract the second equation from the first...
(x+7y=64)
-(x+3y=28)
_________
4y=36 divide both sides by 4
y=9, which makes x+7y=64 become:
x+63=64
x=1
So the solution to the system of equations is the point (1,9)
4)
Subtract the second from the first:
4x-4y=24
-(x-4y=3)
_______
3x=21 divide both sides by 3
x=7, which makes x-4y=3 become:
7-4y=3
-4y=-4
y=1
So the solution to the system of equation is the point (7,1)
16 servings
Quart = 4 cup
4 quarts(4) = 16 cups
Answer:
The number of gallons of 20% alcohol solution is 12 and the number of gallons of 60% alcohol solution is 4
Step-by-step explanation:
Let
x ----> the number of gallons of 20% alcohol solution
y ----> the number of gallons of 60% alcohol solution
we know that
20%=20/100=0.20
60%=60/100=0.60
30%=30/100=0.30
x+y=16
x=16-y ------> equation A
0.20x+0.60y=16(0.30) ------> equation B
Solve by substitution
Substitute equation A in equation B and solve for y
0.20(16-y)+0.60y=16(0.30)
3.2-0.20y+0.60y=4.8
0.40y=4.8-3.2
0.40y=1.6
y=4 gal
Find the value of x
x=16-y
x=16-4=12 gal
therefore
The number of gallons of 20% alcohol solution is 12 and the number of gallons of 60% alcohol solution is 4