Answer:

Step-by-step explanation:
The sum you are trying to understand is this.

Remember that in general when you have a geometric series
you have that
and that equality is true as long as
.
Therefore here we have
and 
Therefore we can use the formula and

The problem here is: Too many words.
If you boil the problem down to the bare facts, the question is:
"$210 is 15% of what number ?"
I'm pretty sure you can take it from there,
but here's the rest of it anyway:
$210 = 15% of (March amount)
$210 = 0.15 x (March amount)
Divide each side by 0.15 : $1400 = March amount .
Check:
1400 + 210 = 1610
1.15 x 1400 = 1610 yay!
Answer:
6%
Step-by-step explanation:
This is an honest guess just because you are not given the content of 2 out of the 3 bags. When starting at 100 percent of the makeup of the porridge you can then divide that by 3 to get the content of 1 bag. You will get around 33 then you find what 20% of 33 is which is closest to either 6 percent.
Answer:
Since A={a,b}, then
. Remember that the Cartesian Product of two sets A, B is defined by
. Then
