Answer: 21
Step-by-step explanation:
we have two simple equations:
1) 70=100%
2) x=30%
where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:
70/x=100%/30%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.
7. Solution for what is 30% of 70
70/x=100/30
(70/x)*x=(100/30)*x - we multiply both sides of the equation by
70=3.33333333333*x - we divide both sides of the equation by (3.33333333333) to get x
70/3.33333333333=x
The fore, the answer is 21
Answer:
C
Step-by-step explanation:
Answer:

Step-by-step explanation:
we know that
The density is equal to the mass divided by the volume
Let
x-----> the mass of marble
y----> the volume of marble
z----> the density of marble

in this problem we have


substitute and solve for x


Answer:
A
Step-by-step explanation: