The number of kilograms of water in a human body varies directly as the mass of the body. an 84-kg person contains 56 kg of water. how many kilograms of water are
in a 63-kg person?
kg of water are in a 63-kg person.
(simplify your answer.)

Step-by-step explanation: Let the number of kilograms of water in human body be N and the mass of the body be M, from the statement ,

N ∝ M

introducing proportionality constant , we have

N = KM

Given from the second statement , N = 56 , M = 84

substitute the given values into the equation to get the constant

i.e 56 = K x 84

     56/84 = k

therefore k = 2/3

substitute the value of K into the equation

i.e N = 2/3 M

Finally , to find N when M is 63

⇒ N = 2/3 x 63

therefore N = 42

There are 42 kg of water in a 63 kg person

1/4 because there is 4 grades.