A human body is 55% water. A person has a mass of 78 kg. How many kg. of water is in this person's body?

0.55 x 78 = ?

To find how many kilograms of water are in a person's body, you can multiply their body mass by the percentage of water content.

First, calculate the amount of water by multiplying the percentage by the mass:

Water content = 55% (0.55) * 78 kg

Multiply 0.55 by 78 kg:

Water content = 0.55 * 78 kg

Water content = 42.9 kg

Therefore, the water content in this person's body is approximately 42.9 kg.