Ratio + time - math problems

Number of problems found: 112

Two xeroxes
The performances of the two copiers are in the ratio 3: 4. A machine with higher power will make 7,200 copies in one hour. How many copies will both machines make together in 5 hours?
Mr. Ben
Mr. Ben drives bricks to the construction site. If he drove three times a day, he would make bricks in 8 days. How many times a day would he go every day to be done 2 days earlier?
Everyone drinks the same
24 bricklayers drink 72 beverage bottles a day at the construction site. How many bottles would 19 bricklayers need? Everyone drinks the same.
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.
Chimney and tree
Calculate the height of the factory chimney, which casts a shadow 6.5 m long in the afternoon. At the same time, a 6 m high tree standing near it casts a shadow 25 dm long.
On the
On the map of Europe made at 1: 4000000, Bratislava and Paris' distance is 28 cm. At what time an airplane flying 800 km/h will fly this journey?
Six workers
Six workers earned a total of CZK 12,600 per week on the construction site (5 working days). How much do 7 workers earn in 10 days with the same daily average salary?
Five combers
Five combers harvest 12 rows of strawberries in 4 hours. How many rows of strawberries will two combers harvest in 10 hours?
Age of family
The age of father and son is in the ratio 10: 3. The age of the father and daughter is in a ratio of 5: 2. How old are a father and a son if the daughter is 20?
The shadow
The shadow of a 1 m high pole thrown on a horizontal plane is 0.8 m long. At the same time, the shadow of a tree thrown on a horizontal plane is 6.4 m. Determine the height of the tree.
Diggers
The excavation was carried out in 4 days and 5 workers worked on it for 7 hours a day. Determine how long it would take to excavate if 7 workers worked on it 8 hours a day.
Lookout tower
Calculate the height of a lookout tower forming a shadow of 36 m if at the same time a column 2.5 m high has a shadow of 1.5 m.
Worker's performance
15 workers paint 180 m fence in 3 days. In how many days will 9 workers paint a 360 m fence? We assume that each worker have the same, constant and unchangeable performance.
Father and daughter
Father is 36 years old, daughter is 20 years less. What will be the ratio between them when they are 10 years more?
Ages
Father is 36 years old, and his daughter is 4 years old. Write down the ratio of the age of father and daughter. In what ratio will the ages of father and daughter after 4 years?
Age ratio
Janko is 14 years old. The age ratio of Janka and Zuzka is 2: 3. What was the ratio seven years ago?
Rate 3
A liquid is heated at a rate of 5 degrees Celsius per minute. If the temperature now is at 39 degrees Celsius, how long will the temperature by 94 degrees Celsius?
Two trains
Two trains departed from City A and City B against each other. They met after some time. The first train then took 9 hours to reach city B, and the second train took 4 hours to reach city A. In what proportion were the train speeds?
Cheetah vs antelope
When the cheetah began chasing the antelope, the distance between them was 120 meters. Although the antelope was running at 72km/h, the cheetah caught up with it in 12 seconds. What speed was the cheetah running?
Kilowatt-hours
If the Lewis family used 648 kilowatt-hours of electricity in 12 days, how many kilowatt-hours should they use in 24 days at the same usage rate?