Need a little help with this ratio question

  • Thread starter tehmatriks
  • Start date
  • Tags
    Ratio
Let the tank be full when it hold x liters of oil. In the first case it is 3/4 full, so the oil in the tank will be (3/4)xliters. Then 100 liters of oil are used. So the oil remaining in the tank is (3/4)x - 100 liters. This is then 2/3 full. So (2/3)x liters is the oil in the tank. So (3/4)x - 100 = (2/3)x. Now solve for x.
  • #1
tehmatriks
40
0

Homework Statement


A tank was 3/4 full of oil. 100 litres of oil were then used. If it was then 2/3 full, how many litres does the tank hold when full


Homework Equations





The Attempt at a Solution


umm, I am not even sure how to get started, i know that 3/4 = 75% and 2/3 = 66.6%
but can't quite wrap my head around it. so yea, i need some help, thanks in advance
 
Physics news on Phys.org
  • #2
tehmatriks said:

Homework Statement


A tank was 3/4 full of oil. 100 litres of oil were then used. If it was then 2/3 full, how many litres does the tank hold when full


Homework Equations





The Attempt at a Solution


umm, I am not even sure how to get started, i know that 3/4 = 75% and 2/3 = 66.6%
but can't quite wrap my head around it. so yea, i need some help, thanks in advance

If 0.1 liters is the difference between those two fractions, how much is 100% ?
 
  • #3
Let x = the number of liters in a full tank.

Now convert these sentences into one equation.
A tank was 3/4 full of oil. 100 litres of oil were then used. It was then 2/3 full.
 
  • #4
Hi:

The difference between a tank that is 3/4 full and a tank that is 2/3 full is 100 litres. The word "difference" implies 'subtract'. So if (3/4 - 2/3) = 100l, what is the volume of the whole tank?
 
  • #5
accystan said:
Hi:

The difference between a tank that is 3/4 full and a tank that is 2/3 full is 100 litres. The word "difference" implies 'subtract'. So if (3/4 - 2/3) = 100l, what is the volume of the whole tank?
As stated, this isn't much help. Your equation above says that 3/4 - 2/3 = 100L, which isn't true.
 
  • #6
Mark44 said:
As stated, this isn't much help. Your equation above says that 3/4 - 2/3 = 100L, which isn't true.

I'm not sure why you're saying this is not true. Can you explain why?

Continuing...

If 3/4 - 2/3 = 100 l.

then 1/12 = 100 l.

and tank capacity is 1200 l.
 
  • #7
accystan said:
I'm not sure why you're saying this is not true. Can you explain why?

Continuing...

If 3/4 - 2/3 = 100 l.

then 1/12 = 100 l.

and tank capacity is 1200 l.

Since when does the number 1/12 equal 100? That is what you are saying. I know what you are thinking, and I suspect Mark44 does too, but you are missing a crucial piece in your "equation."

And by the way, you're not supposed to post solutions here.
 
  • #8
accystan said:
I'm not sure why you're saying this is not true. Can you explain why?

Continuing...

If 3/4 - 2/3 = 100 l.

then 1/12 = 100 l.

and tank capacity is 1200 l.

Now that you've shown complete solution to the OP...

What Mark44 is trying to say is that: "1/12 = 100l" is not a valid statement. 1/12 is a real number, how can it equal to 100l? 1/12 of what?
 

1. What is a ratio?

A ratio represents the proportional relationship between two quantities. It is expressed as a comparison of two numbers or quantities using a colon (:) or as a fraction.

2. How do I solve a ratio question?

To solve a ratio question, you need to first identify the quantities being compared and then determine the equivalent form of the ratio. This can be done by simplifying the ratio to its lowest terms or by converting it into a fraction or decimal.

3. Can ratios be simplified?

Yes, ratios can be simplified to their lowest terms. This means that the numerator and denominator of the ratio cannot be divided by the same number to produce a smaller ratio.

4. What is the purpose of using ratios in science?

Ratios are commonly used in science to compare different measurements or quantities. They allow scientists to express relationships and make comparisons between different variables, which can help in understanding patterns and relationships in data.

5. How are ratios different from fractions?

Ratios and fractions are similar in that they both compare two quantities. However, ratios are typically written using a colon or as a fraction, while fractions are written with a numerator and denominator separated by a horizontal line. Additionally, ratios can be simplified to their lowest terms, while fractions can also be simplified but may not necessarily be in their lowest form.

Similar threads

  • Precalculus Mathematics Homework Help
Replies
6
Views
763
  • Precalculus Mathematics Homework Help
Replies
3
Views
1K
  • Precalculus Mathematics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
12
Views
911
  • Precalculus Mathematics Homework Help
Replies
1
Views
506
  • Precalculus Mathematics Homework Help
Replies
11
Views
1K
  • Precalculus Mathematics Homework Help
Replies
2
Views
560
  • Precalculus Mathematics Homework Help
Replies
7
Views
2K
  • Precalculus Mathematics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
896
Back
Top