Question

The combined average weight of an okapi and a llama is 450 kilograms. The average weight of 3 llamas is 190 kilograms more than the average weight of one okapi.

On average, how much does an okapi weigh, and how much does a llama weigh?

Answer 1

We can first assign variables to an okapi and a llama.

Let us use x for okapi's, and y for llamas.

In the first sentence, we can set up our first equation:


`x+y=450`

We can then set up the second equation with the second sentence:


`3y=190+x`

Then, we are asked to solve for x and solve for y.

What we can do here is to get both equations in the format of:
`x+y=b`. Let us do that now.


`x+y=450`

`-x+3y=190`

What we can do now is solve this just like a system of equations using the elimination method. Let's add both of the equations together from top to bottom - the x's cancel out so we are left with:


`4y=640`


`y=160`

The average weight of one llama is 160 kg.

Let us then plug in 160 for y into one of the first two equations (either of the two will work, just a matter of preference):


`x+160=450`


`x=290`

The average weight of one okapi is 290 kg.

Therefore, through this method, we are able to determine that the average weight for one okapi is 290 kg, and the average weight for one llama is 160 kg.