# Expression of a variable from the formula + simple proportion - practice problems

#### Number of problems found: 15

- The cost 4

The cost to tile a floor that measures 7 x 6 square feet is $ 2,100. How much will it cost to tile a floor that measures 11 x 13 square feet? - Vertical rod

The vertical one-meter-long rod casts a shadow 150 cm long. Calculate the height of a column whose shadow is 36 m long at the same time. - Save trees

25 tons of old paper will save 1,600 trees. How many tons of paper is needed to save the 32 trees in the park? - The farmer

The farmer calculated that the supply of fodder for his 20 cows was enough for 60 days. He decided to sell 2 cows and a third of the feed. How long will the feed for the rest of the peasant's herd last? - Hectares of forest

12 workers plant 24 ha of forest in 6 days. In how many days will 15 people and 12 people plant the same area? - Mixture of nuts

Alice bought a mixture of nuts containing cashew nuts, hazelnuts and peanuts in a ratio of 1: 2: 3. Calculate the weight in grams of the whole mixture if the peanuts weigh 90 g. - Sugar production

From 1 ton of beet, 150 kg of sugar is produced. To clean 1 ton of sugar, 450 kg of lime is consumed. Calculate how many kgs of lime is consumed when processing 1 ton of sugar beet? - Bicycle gear

The pedal bicycle wheel has 56 teeth and a rear 20 gear tooth. How many times does the bicycle wheel turn when you make 20 turns of the pedal wheel? - Book reading

If we read the book at a speed of 15 pages a day, we read it 3 days before we read it at a speed of 10 pages per day. If I read at 6 pages per day, how many days will I read the book? - Wood harvesting

The harvested wood is bundled from the forest to a sawmill. The driver makes the journey four times a day, and the work takes him 8 days. How many times would he have to go daily to get the job done 2 days earlier? - Trapezoid - intersection of diagonals

In the ABCD trapezoid is AB = 8 cm long, trapezium height 6 cm, and distance of diagonals intersection from AB is 4 cm. Calculate the trapezoid area. - R1+R2 in parallel

The resistance ratio of the first and second resistors is 3: 1 and the current flowing through the first resistor is 300 mA. What current flows through the second resistor (resistors connected in parallel)? - Bicycle gears

The toothed wheel on the bicycle pedal has 40 teeth, the wheel on the rear wheel has only 16 teeth. How many times does the rear wheel turn if the pedals rotate 50 times? - Painting rooms

If Dano paints three hours daily, he complete in 7.5 days. How many hours a day would have to work to finish the job 1.5 days earlier? - Painters

Five painters painting the fence for eight days. How many days over will take work if paint the fence only four decorators?

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Expression of a variable from the formula - practice problems. Simple proportion - practice problems.