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

An illustration of the letter 'A' in a speech bubbles

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

We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

  • 30,000+ book summaries
  • 20% study tools discount
  • Ad-free content
  • PDF downloads
  • 300,000+ answers
  • 5-star customer support
Start your 48-Hour Free Trial