Answer:
17
Step-by-step explanation:
If a container holds 100 of salt and 75% of it is salt, then the amount of salt is 0.75 * 100.
Amount of salt in initial solution: 0.75 * 100 = 75
If we evaporate some X amount of water, we will get that 75 is 90% of the remaining water. Let that remaining amount of water be y mL. So 90% of the y remaining solution is going to also be 75.
75 = 0.90y
We can rearrange this by dividing by 0.75 on both sides.
75/0.90 = 0.75y/0.90
The 0.90 on the right cancel and we are left with:
75/0.90 = 83
So, the initial 75% salt solution had 100 .
The ending 90% salt solution is 83 .
So the amount of water that needs to be evaporated is 17
I just copy it but I rearranged it
