The body of an adult is 70% water. What is the mass of water in the human body, which weighs 76kg?

It is known from the condition that the body of an adult is 70% water. In order to find what is the mass of water in the human body, which weighs 76 kg, we will compose and solve the proportion.

Let’s take the human body weight as 100%. And using the variable x, we denote the weight of water in the body of an adult.

We make the proportion.

76 kg – 100%;

x kg – 70%;

We got the proportion:

76 / x = 100/70;

We are looking for a variable as an unknown factor:

x = (76 * 70) / 100 = 5320/100 = 53.2 kg of water in the body of a 76 kg person.