Question

Fresh raspberry contains 80% water. dried raspberry contains only 20% water. what weight of dried raspberry can you get from 36 lb of fresh berries?

Answer 1

There 2 ways to solve this

1-      Directly :

80% of water in the fresh berries è 20% of water in the dried berries

36 Ibs of the fresh berries è X Ibs of the dried berries

X = $\frac{36 * 20}{80}$ = 9 Ibs

 

2-      If you do not understand the first method, the second one is more explicit:

First, we gonna calculate the weight of the berries without water (dehydrated):

36 * 80% = 28.8 Ibs    (of water in the berries)

Then:

36 – 28.8 = 7.2 Ibs (of completely dehydrated berries)

 

Next, we gonna add 20% of water in the dehydrated berries:

X (total weight of dried berries) è 100%

7.2 Ibs of dehydrated berries è 80%

X =   $\frac{7.2 * 100}{80}$   = 9 Ibs