Question

Raul and his friends, each of whom weighs 1/20 of a ton, are standing on a truck scale. The total weight shown by the scale is 3/4. How can you find the total number of people on the scale when raul and his friends are weighed?

Answer 1

There are 15 friends

Explanation:

The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three.

If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other) in the same proportion, the rule of three applies as follows:

a ⇒ b

c ⇒ x

Then:
`x=(c*b)/(a)`

where a, b and c are known values ​​and x is the value to be calculated.

In this case, the rule of three applies as follows: if 1/20 of a ton is the weight of 1 person, 3/4 of a ton is the weight of how many people?

`number of people =((3)/(4) of a ton*1 person )/((1)/(20) of a ton)`

or, what is the same,

number of people*
`(1)/(20)` =
`(3)/(4)`

Solving:

number of people= 15

There are 15 friends