How to answer? I'm confused on the second part

Question

The human body is 65
% water. A certain man weighed 150 lb. After 1 year on a diet, his weight decreased by 15
%. Round all the calculations to two decimal points.

 

a. Before the diet, how much of the man's weight was water? which equals : 97.50

 

b. After the diet, how much of the man's weight was water? I have no idea how write it the problem out to solve it, but the answer is 82.88

Answer 1

The initial weight is 150 lb. You may express 15 percent as 0.15, 15/100, or 15% as needed.

 

a. before weight loss, (65/100)*150 = 97.5 lbs of his weight was water.

 

b. After weight loss,  

       65 percent of (original weight - 15%of original weight)

           (65/100)*(    150 -                    (15/100)(150) )     = 82.875 lb was water

   Rounded to 2 decimal places, that is 82.88 lb

Answer 2

Assuming the the 65% water is constant for both 150 lb person and that same person who lost 15% weight.

 

we will have the following

 

100% = 150 lbs

Water weight = 150 lbs * 0.65 = 97.5 lbs

Other Total = 150 lbs * 0.35 = 52.5 lbs

 

 

A) as you have stated the weight here 97.50 lbs

 

B) After the diet, how much of the man's weight was water?

If 100 % = 150 lbs we can say 150 lbs*(100%-15%) = 127.5 lbs

therefore after the mans diet he weighs 127.50 lbs

now solve the water weight 127.50lbs *.65 = 82.875 lbs which rounds to 82.88 lbs

 

i hope this helps!

 

-Kiran

 

Answer 3

1.00 - 0.15 = .85 (he now weighs 85% of his previous weight)

 

150 * .85 = 127.5 (85% of 150 is 127.5)

 

127.5 * .65 = 82.875 (65% of 127.5 is 82.875)

 

82.875 rounds up to 82.88