D. Although I'm not 100% sure
We do so to follow the rule of divisibility of each term(numbers).
<h2 /><h3><u>The Rule of Divisibility:</u></h3>
The rule of divisibility of numbers is a method applied in mathematics used to determine if a number or set of numbers is divisible by a particular integer without any remainder.
Let assume that we have a series of numbers;
From the rule of divisibility, since all the numbers are multiples of 2;
We can deduce that 2 can be the factor that is pulled out from the series to divide each term in the sum.
Learn more about the rule of divisibility here:
brainly.com/question/840412
Answer:
28 non-blue marbles.
Step-by-step explanation:
Initial probability of choosing a blue marble = 4/12
Let the number of non-blue marbles to be added be x.

(cross multiply)

The solution would be like this for this specific problem:
Volume of a cylinder = pi * r^2 * h
Volume of a cone = 1/3 * pi * r^2 * h
Total Height = 47
Height of the cone = 12
Height of the cylinder = 35
If the top half is filled with sand, then:
volume (sand) = pi * 4^2 * 36
volume (cone) = 1/3 * pi * 4^2 * 12
Total volume = 1960.353816 cubic millimeters
353816 / (10 * pi) = 62.4 seconds.
It will take 62.4 seconds until all of the sand has dripped to the bottom of the hourglass.
X - invested for the money at 11%
70 000 - x - deposited at 12%
0.11x + 0.12(70000-x)=7900
0.11x + 8400 - 0.12x = 7900
8400- 7900 = 0.01x
500 = 0.01x
x=50 000 invested at 11%
rest (20K) invested at 12%