Answer:
1000 runners
Step-by-step explanation:
Take total number of runners to be -----------x
90% of x managed to complete the marathon= 90/100 × x =0.9x
30% of those who completed the marathon were men= 30% × 0.9x
=0.3×0.9x= 0.27x
=270 men completed the marathon; this means
0.27x=270--------------------------------find x by dividing both sides by 0.27
x= 270/0.27
x=1000 runners
The answer to your question is -304
A function

is periodic if there is some constant

such that

for all

in the domain of

. Then

is the "period" of

.
Example:
If

, then we have

, and so

is periodic with period

.
It gets a bit more complicated for a function like yours. We're looking for

such that

Expanding on the left, you have

and

It follows that the following must be satisfied:

The first two equations are satisfied whenever

, or more generally, when

and

(i.e. any multiple of 4).
The second two are satisfied whenever

, and more generally when

with

(any multiple of 10/7).
It then follows that all four equations will be satisfied whenever the two sets above intersect. This happens when

is any common multiple of 4 and 10/7. The least positive one would be 20, which means the period for your function is 20.
Let's verify:


More generally, it can be shown that

is periodic with period

.
Answer:
1/6z.
Step-by-step explanation:
25z^2 / 150z^3
25 divides 6 times into 150 and z^3 / z^2 = z
so the answer is 1/6z.