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.
Answer:
3
Step-by-step explanation:
Answer:
an = n -27
Step-by-step explanation:
The general term (an) of an arithmetic sequence is given by the formula ...
an = a1 + d(n -1)
where a1 is the first term and d is the common difference.
Your sequence has a first term of a1 = -26 and a common difference of d = 1. Putting these values into the formula gives ...
an = -26 + 1(n -1)
This can be simplified to ...
an = n - 27
It’s a little blurry but i can help