Math

posted by .

A man selling fruit has only three weights. But with them he can weigh any whole number of kilograms (from 1 kg to 13 kg) inclusive on his balance.

What weights does he have?

Responses


math - Kalyan, Friday, September 5, 2008 at 4:38am
The man had 1kg, 3kg and 9 kg weights.


How do you set it up to get this answer? Any ideas?

  • Math -

    You can prove to yourself that 1,3 and 9 work. With them, you can form counterbalances of
    1, 2 (3-1), 3, 4 (3+1), 5 (9-1-3),6 (9-3), 7 (9+1-3), 8 (9-1), 10 (9+1), 11 (9+3-1), 12 (9+3) and 13 (9+3+1)

    A minus sign means putting the weight on the same side of the balance as the weighed object.

    Proving that other combinations will not work is harder, but is not necessary.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. algebra

    A man selling fruit has only three weights; but with them he can weigh any whole number of kilograms from 1 kg up to 13 kg, inclusive on his balance. What weights does he have?
  2. math

    A man selling fruit has only three weights. But with them he can weigh any whole number of kilograms (from 1 kg to 13 kg) inclusive on his balance. What weights does he have?
  3. math

    ou have only four weights and a balance scale. If your task is to weigh ANY load from 1 to 40 kg (integers only) then how much should each of your 4 weights weigh?
  4. Math

    An apothecary has a set of five weights for use in the pans of his balance. By proper selection of weights, he is able to measure every multiple of 0.5 g, from 0.5 g up to a total of the five weights together. If the arrangement of …
  5. algebra

    A shipping clerk wishes to determine the weights of each of the 4 boxes. Each box weighs a different integer amount less than 70 kg. Unfortunately, the only scales available measure weights in excess of 70 kg. The clerk therefore decides …
  6. calculus

    The chemistry teacher at Stevenson High School is ordering equipment for the laboratory. She wants to order sets of five weights totaling 121 grams for each lab station. Students will need to be able to weigh every integral weight …
  7. statistics

    .) A hospital in a large city records the weight of every infant born at the hospital. The distribution of weights is normally shaped, with a mea n ยต= 2. 9 kilograms and a standard deviation o- = 0 .45. Determine the following: a. …
  8. UNM

    Suppose that the average weight of students in a statistics class is 75.5 kilograms with a standard deviation of 10.3 kilograms. A. 45% of the student weights are above ____ kilograms?
  9. Physics

    At the gym, a woman lifts 40 kilograms of weights on the leg press machine. It takes her 0.5 seconds to raise the weights a vertical distance of 0.4 meters. How much power does the woman generate when lifting the weights?
  10. Math

    The sum of the weights of a dog and cat is 27 pounds. The dog weights an odd number of pounds. Each animal's weight is counting number. If he weights twice as much as she does, what are the weights of the dog and the cat?

More Similar Questions