# Direct relationship - 8th grade (13y) - math problems

- Six students

Two pupils painted the class in four hours. How long will it take for six pupils? - Blueberries

5 children collect 4 liters of blueberries in 1.5 hours. a) How many minutes do 3 children take 2 liters of blueberries? b) How many liters of blueberries will be taken by 8 children in 3 hours? - Assembly parts

Nine machines produce 1,800 parts on nine machines. How many hours will it produce 2 100 parts on seven such machines? - Cook on gas

The gas cylinder will last for 30 weekends for 2 hours of daily cooking. How many days will we be able to cook on a new cylinder when we cook 3 hours a day? - Shadow

A meter pole perpendicular to the ground throws a shadow of 40 cm long, the house throws a shadow 6 meters long. What is the height of the house? - Proportion 2

A car is able to travel 210 km in 3 hours. How far can it travel in 5 hours? Put what kind of proportion is this and show your solution. - Divide

Divide area of rectangles with dimensions 32m and 10m by the ratio 7: 9. What area corresponds to a smaller section? - Air thermal

Imagine that a unit of air rises at 3000 meters high, if temperature decreases 6 degrees celcius for every 1000 meter, what will be its temperature at 1400 meters, 2000 meters, 2500 meters and when it reaches the 3000 meter elevation. Starting temperature. - Image reduction

To say that I am mathematically challenged is a gross understatement! I'm trying to help my friend determine how to calculate percentages of reduction or enlargement for a quilt pattern. She is creating a drawing of a cute picture which will become a pie - Ratio of sides 2

The ratio of the side lengths of one square to another is 1:2. Find the ratio of the area of the two squares. - Bulbs

There are 875 identical light bulbs in the sports hall lightning for 2 hours. How long does it lightning 100 this light bulbs? - Sick

Six seamstresses should make 60 shirts in five business days. After three days two seamstresses were sick. How many days have the remaining seamstresses to finish contract? - Five inlets

The tank can be filled with five equally powerful inlets. If the tank is filled by four of these inlets, it takes a total of 30 minutes to fill one-third of the tank. How many minutes does it take to fill an empty tank if it is filled with all five inlets? - Three 43

Three brothers inherited a cash amount of 62,000 and they divided it among themselves in the ratio of 5:4:1. How much more is the largest share than the smallest share? - In the

In the national park, the ratio of the wooded area to grassland is 4: 1. The total area is 385km2. What area is wooded? - Painters

Ten painters paint the school in 20 days. How many days do four painters paint the school at the same pace of work? - Apples

School kitchen bought 36kg apples for 12 kc/kg. How many kilograms of apples 1/4 cheaper can they buy for the same money? - Rectangle 3-4-5

The sides of the rectangle are in a ratio of 3:4. The length of the rectangle diagonal is 20 cm. Calculate the content of the rectangle. - Fence and scale

The garden with 80 m of fencing is draw on plan as a square with a side length of 4 cm. At what scale is this plan made? - Sun rays

If the sun's rays are at an angle 60° then famous Great Pyramid of Egypt (which is now high 137.3 meters) has 79.3 m long shadow. Calculate current height of neighboring chefren pyramid whose shadow is measured at the same time 78.8 m and the current hei

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