Ratio Calculator
Solution:
x = 5/2 = 2.5
2:2.5 = 4:5
Solve ratios or proportions a:b=c:d for the missing value. Missing value mark as variable x (or other a-z). We also accept decimals and some basic mathematical operations. Ratios enter in the form such as:
1/x = 3/8
180 = 1:2 divide a number in the ratio
2:x = 4:5
x/2 = 3:5
2.2/x = 5.5/6.6
5/6 = x:12
-8/5 = 12/y
-8/5 = (y+1)/12
A ratio in math is a way to compare two or more quantities by showing the relative sizes of the quantities. It expresses how much of one quantity there is compared to another. Ratios are used in many real-world situations, such as cooking, mixing ingredients, scaling maps, and comparing proportions.
Key Concepts of Ratios
1. Definition:
- A ratio compares two or more numbers or quantities. It is written in the form a : b or ab , where a and b are the quantities being compared.
2. Simplification:
- Ratios can be simplified by dividing both terms by their greatest common divisor (GCD). For example:
- The ratio 6 : 9 can be simplified to 2 : 3 by dividing both terms by 3.
3. Types of Ratios:
- Part-to-Part Ratio: Compares one part of a whole to another part of the same whole. For example, in a group of 5 boys and 3 girls, the ratio of boys to girls is 5 : 3 .
- Part-to-Whole Ratio: Compares one part of a whole to the entire whole. For example, in the same group, the ratio of boys to the total number of children is 5 : 8 .
4. Equivalent Ratios:
- Ratios that represent the same relationship but are written with different numbers. For example:
- 2 : 3 is equivalent to 4 : 6 or 6 : 9 .
5. Proportions:
- A proportion is an equation that states that two ratios are equal. For example:
- 23 = 46 is a proportion.
How to Write and Use Ratios
Example 1:
Writing a Ratio- Suppose there are 4 apples and 6 oranges. The ratio of apples to oranges is:
4 : 6 or 46
- This can be simplified to:
2 : 3 or 23
Example 2:
Using Ratios in Real Life- A recipe calls for 2 cups of flour and 1 cup of sugar. The ratio of flour to sugar is:
2 : 1
- If you want to double the recipe, the ratio remains the same, but the quantities become:
4 cups of flour : 2 cups of sugar
Applications of Ratios
1. Scaling:
- Ratios are used to scale objects up or down. For example, if a map has a scale of 1 : 100,000 , 1 cm on the map represents 100,000 cm in real life.
2. Mixing:
- Ratios are used to mix ingredients in recipes, paints, or chemicals. For example, a paint mixture might use a ratio of 3 : 1 (3 parts paint to 1 part thinner).
3. Finance:
- Ratios are used in finance to compare quantities, such as debt-to-income ratio or price-to-earnings ratio.
4. Probability:
- Ratios are used to express probabilities. For example, the probability of rolling a 3 on a six-sided die is 1 : 6 .
Summary
A ratio is a mathematical tool for comparing quantities. It can be written in the form a : b or ab , simplified, and used in various real-world applications. Understanding ratios is essential for solving problems involving proportions, scaling, mixing, and more.
Ratio questions and word problems
- Train
A train travels a section of line in 55 minutes at a speed of 70 km/h. At what speed would it need to travel to shorten the journey time by 16 minutes? - Gain
Find the gain whenever the output power is 18x the input power. - Translations
Suppose I am going to translate the book six pages per day. Suppose I translate it four days earlier than if I translated five pages a day. If I translate four pages a day, I translate it for how many days.....? - Trapezoid - diagonal
A trapezoid has a length of diagonal AC crossed with diagonal BD in the ratio of 2:1. The triangle created by points A, the cross point of diagonals S, and point D has an area 164 cm². What is the area of the trapezoid? - Train from Prague
The first train from Prague started at 8:00 AM at 40 kilometers per hour. Train from Ostrava started at 9:20 at 80 km per hour. How many hours and how far from cities with trains meet if the distance of cities is 400 km. - Lamp brightness
Ten lamps with a certain luminosity are needed to illuminate the rooms. How many lamps with 2.5 times more brightness are needed for the same lighting in the same room? - Copiers
The new copier is copying a folder of papers 5 minutes faster than the old one. The operator used a new one, but it was out of toner, and the exchange took 5 minutes at that time, copied on the old one. The whole work was done in 9 min. How long would the - Sputnik
The first Earth satellite was flying at a speed of 8000 m/s. At that rate, he circled the Earth in 82 minutes. Jet flies at an average speed of 800 km/h. How long would it take to circle the Earth around? - Blueberries
Mike and Anthony have a total of 1,580 blueberries. Mike and Anthony have them in the ratio of 2:3. Determine how much each of them has. - Tree shadow
The tree perpendicular to the horizontal surface has a shadow 8.32 meters long. At the same time, a one-meter rod perpendicular to the horizontal surface has a shadow 64 cm long. How tall is the tree? - Cooling liquid
Cooling liquid is diluted with water in a ratio of 3:2 (3 parts by volume of coolant with two volumes of water). How many coolant volumes must be prepared for a total of 0.7 dm³ (liters) of the mixture? - Perimeter - rectangle
The perimeter of the rectangle is o cm. One side is one-third the length of the other. Express the lengths of both sides of the rectangle using its perimeter - Sugar production
From 1 ton of beet, 150 kg of sugar is produced. 450 kg of lime is consumed to clean 1 ton of sugar. Calculate how many kgs of lime are consumed when processing 1 ton of sugar beet. - Cone side
Calculate the volume and lateral surface area of a cone with a height of 10 cm, given that the axial cross-section has an angle of 30° between the height and the slant side. - Geometric plan
At what scale is the building plan if one side of the building is 45 m long and 12 mm long on a plan?
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