A percentage changes just one point. The weight, however, does not react with timidity. This riddle is small and leaves a mark.
Watermelons in the sun
Riddle statement
A load of watermelons weighs 100 kilos and is made up of 99% water.
After several days in the sun, it is still the same load, but now it is made up of 98% water.
How much does it weigh now?
Show solution
Solution
At the beginning, 99% of 100 kilos is water, so the remaining 1% is dry matter.
That means that the dry matter weighs 1 kilo.
After part of the water evaporates, the dry matter still weighs 1 kilo, but now it represents 2% of the total.
If 1 kilo is 2% of the new weight total:
$1 \div 0{,}02 = 50 \t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\text{ kilos}$
The shipment now weighs 50 kilos.