Reason + inverse relationship - practice problems
Number of problems found: 30
Three people pick strawberries from 48 rows in 8 hours. How many hours do five people need to pick strawberries from 20 rows?
- Poplar shadow
The nine-meter poplar casts a shadow 16.2 m long. How long does a shadow cast by Peter at the same time, if it is 1.4 m high?
- 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?
- Fast tourists
If three tourists pass the route in 5 hours, how long will the same route take six equally fast tourists?
Ten painters paint the school in 20 days. How many days do four painters paint the school at the same pace of work?
- Assembly parts
Nine machines produce 1,800 parts on nine machines. How many hours will it produce 2 100 parts on seven such machines?
- The work
The work was to be done by 150 workers. At the beginning of their work, their number reduced by 40, which increased the time of work by 5 and 1/3 of the schedule. How long did work take?
I have a box of chocolate - white, milk and dark. The ratio of white to milk with dark is 3: 4. The ratio of white and milk to dark is 17: 4. Calculate what is the ratio between white, milk, dark chocolate.
School kitchen bought 36kg apples for 12 kc/kg. How many kilograms of apples 1/4 cheaper can they buy for the same money?
The baker makes from 10 kg of flour 12 kg dough. How much flour he need to make a 100 kg dough?
- Sea water
One tonne of sea water contains 25 kg of salt. How many tonnes of sea water need to be evaporated to obtain 1 tonne of salt?
- Forth and back
Car drive from point A to point B at speed 78 km/h and back at 82 km/h. If went there and back at speed 81 km/h journey would take five minutes less. What is the distance between points A and B?
- Three numbers
What are three numbers that have the property: the sum of the first and second numbers' reciprocals is 12/7, the first and third 11/24, and the second and the third 3/8.
- New computer
New computer process a certain amount of data for 6 hours. For how many hours will process the same amount of data older computer that has a quarter lower performance?
Farmers'cooperative had a supply of feed for 50 cows to 6 days. Cows got insidious disease after 4 days, 10 of them died. How many total days that farmers had feed for cows?
- Floating floor
In the new building is considered a floating floor worker in each room. 30 minutes lay 9 m² of the floor. How long 3 workers laid the floor in 4 rooms with a total area of 90 m²?
Three copiers will do the same in an hour k copies. How many copies would be done in an hour by four such copiers? ...
- The plan
Students have collected 48 kg of paper which is 16% of the plan. How many kg of paper still have to collect to fulfill the plan?
I embroider tablecloth in 20 days but if I embroider 3/4 hours a day I have embroider it for 15 days. How long do I embroider a day?
Calculate how many 25 kg bags of leveling concrete must be purchased if we leveling room 15 m² to the "height" 6 mm if consumtion is 1.5 kg per square meter and millimeter thickness.
Reason - practice problems. Inverse relationship - practice problems.