Answer:
<em>Y alone can do the piece of work in 30 days.</em>
Step-by-step explanation:
<u>Proportions</u>
Let's make:
N = days for Y to finish the work alone
Since X alone can do it in 15 days, each day he can do a proportion of 1/15 of the piece of work.
Since Y alone can (possibly) do it in N days, each day he can do 1/N parts of the work.
Together, they do

parts of the work per day. We know they can finish it in 10 days, thus:

Rearranging:

The LCM of 10 and 15 is 30, thus operating:

Solving for N:
N = 30
Y alone can do the piece of work in 30 days.
You count each unit square and it counts as one so for number two from point o to point a there are 5 unitsif each side we’re 5 hints and there are 6 sides you multiply five by six to get the answer of 39 for number three
F(n)=f(n+1)=f(n+1)-5 because in the formula you are subtractinng
Part (a)
Independent variable = age
Dependent variable = height
"depends on age" indicates that age is independent.
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Part (b)
Independent variable = amount of sleep
Dependent variable = mood
The key word is "determines". The stuff before this word is the independent variable which affects the dependent variable.
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Part (c)
Independent variable = time water has been running
dependent variable = amount of water in the tub
Time is usually the independent variable
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Part (d)
Independent variable = speed
dependent variable = distance from home
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Part (e)
Independent variable = amount of homework done
dependent variable = speed
This seems like an odd pairing of homework and speed. Could there be a typo? I noticed that part (f) is very similar
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Part (f)
Independent variable = amount of hw that is assigned
dependent variable = amount of homework done
Like with part (a), the stuff before "depends" is the dependent variable