How do you do these math problems and....?

Question

could you explain your answer;
1.
It takes one day to fill the vat with this large pipe, two days with that:The third pipeneeds but one day more: The fourth pipe fills the vat in four: if all four pipes together run. How long before the task is done?
2.
Determine all the values of x and y such that xy, x/y and x-y

are equivelent

Answer 1

the first pipe fill 1 vat per day
the second pipe fills 1/2 vat per day
the third pipe fills 1/3 vat per day
the fourth pipe fills 1/4 vat per day

so 1+(1/2)+(1/3)+(1/4)=25/12 vats per day
which gives 12/25 days per vat or 0.48 days to fill one vat.

as for the second part i can't figure out a single occurance where all of those are equal, but that might just be me.

xy=x/y
xyy=x
yy=x/x
yy=1
y^2=1
y=1

so using that
1x=x/1=x-1
x=x=x-1
it can't work

Answer 2

1: 1 + .5 + .33 + .25 = 2.08
1 / 2.08 = .4807692307
24hrs * .4807692307= 11.5346153846hrs

2: not enough information.
Determine all the values of x and y such that xy, x/y and x-y are what? equivalent? proportionate?

Answer 3

for the first one, put it in terms of vats per day to fill:

1 vat / 1 day = 1 vat/day = 1
1 vat / 2 days = 1/2 vats /day = 0.5
1 vat / 3 days = 1/3 vats / day = 0.3333333
1 vat / 4 days = 1/4 vats / day = .25

Added together, 2.08333 vats per day . The reciprocal is 0.48 days per vat. So your answer is 0.48 days.

Answer 4

put all the pipes as fractions
so
1st pipe: 1 day to fill
1/1
etc.
1/2
1/3
1/4
add them together and you get
25/12
WHAT THE F*CK AM I TALKING ABOUT

Answer 5

I have Trombini Too! =)

#2 is possible. x = -1/2 and y = -1

Answer 6

I don't get what you're trying to say!!!!!


Tell Bob I said hi.

Answer 7

I wish i can help :)