# Doctors need 23, 925ml of blood 4 14 days. A group of ppl will assist, 4 ppl cant. Thus, other members must donate 100ml more. Howmany ppl willdonate? And how much each?

## Expert Answers Let the number of people to donate is x.

Each person will donate y ml of blood.

==> x*y = 23,925...........(1)

Now, 4 people can not donate blood, then additional 100 ml will be added to the amount each person donate.

==> (x-4)(y+100)= 23,925

==> xy + 100x - 4y -400 = 23925........(2)

Now we will solve the system.

We substitute xy= 23925 into (2).

==> 23925 + 100x - 4y -400 = 23925

==> 100x - 4y = 400...........(3)

Now we will substitute with y =`23925/x`

==>  `100x - (4(23925))/x ` = 400

`==> 100x - 95700/x = 400`

Multiply by x.

`==gt 100x^2 - 400x - 95700 = 0 `

`==gt x^2 - 4x - 957 = 0 `

`==gt x= (4+sqrt(3844))/2 = (4+62)/2 = 66/2 = 33`

Then, the number of people needed is 33 people in order to donate 23925 ml of blood in 414 days.

Approved by eNotes Editorial Team

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