There is a math problem in primary school. A ton of grapes lost part of its original water content of 99% during transportation, and the water content dropped to 98%. How many kilograms of grapes are there? The same is true of dried grapes;

Solution: suppose there is grape xkg now;

1 ton = 1000 kg

( 1-98%)x = 1000×( 1-99%)

2%x= 1000× 1%

Solution, x=500

..... Do you understand?