- A gives B and C as many tractors as they already have.
- After some days B gives A and C as many tractors as they have.
- After some days C gives A and B as many tractors as they have.
- Finally each has 24 tractors.

What is the original number of tractors each had in the beginning?

Submitted by Guess the Logo.

A had 39 tractors, B had 21, C had 12.

ReplyDeleteThis is easiest to figure out if you start the math from the end result and work backwards.

I also worked backwards but got a slightly different answer:

ReplyDeleteA: 40, B: 22, C: 12

Carol, you have too many tractors. In your response, you have 40+22+12=74. There need to be 72 tractors total (24x3=72.)

ReplyDeleteAfter round 3

ReplyDeletea b c

24 24 24

A and B both doubled in round 3, so slice them in half to get A and B and subtract from total 72 to get C. That means that the previous nubers must be...

after round 2

a b c

12 12 48

A and C both doubled in round 2, so the previous numbers were...

after round 1

a b c

6 42 24

Rinse and repeat with B and C

originally

a b c

39 21 12

As Jolson laid out so carefully:

ReplyDeleteA 39

B 21

C 12