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?
I can't figure this out
The man had 1kg, 3kg and 9 kg weights.
what is the weiight of a semi trailer
How did you get this answer?
To solve this problem, we need to work backward and find a pattern.
Let's start with the maximum weight of 13 kg. The seller cannot directly measure 13 kg with his available weights since he only has three of them. So, the largest number he can measure directly is either 12 kg or 11 kg. Since both of these numbers are divisible by 3 (the number of weights he has), it means he must have a weight that is divisible by 3.
Now let's move on to the next lower weight, which is 10 kg. Again, he cannot directly measure 10 kg, so he must have a weight that is divisible by 3.
Continuing this pattern, we see that the weights he has must be divisible by 3 for all numbers from 1 kg to 13 kg. Thus, the weights he has can be determined by finding three consecutive numbers that are divisible by 3.
Let's list the numbers from 1 to 13 and check which three consecutive numbers are divisible by 3:
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
From this list, we can see that the three consecutive numbers 9, 10, and 11 are all divisible by 3. Therefore, the weights he has are 9 kg, 10 kg, and 11 kg.
So, the man selling fruit has weights of 9 kg, 10 kg, and 11 kg.