# 9th grade (14y) + direct relationship - examples

- 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 - Beer

After three 10° beers consumed in a short time there are 7.4 g of alcohol in 5 kg adult human blood. How much is it per mille? - Saving

Kevin save € 4620 to buy a car. Yet it lacks save 65% of the car price. How much is the car? - Road repair

Road repair took 16 days for 34 workers if they worked 6 hours a day. How many days take repair same road 33 workers if they work 6 per day? - Bonus

Gross wage was 1113 USD including 16% bonus. How many USD were bonuses? - Accidents

The count of accidents in 1993 caused 8009 women which is 7.1%. How many men caused the accidents? - Copiers

Three copiers will do the same in an hour k copies. How many copies would be done in an hour by four such copiers? ? - Division

Three siblings Helena, Oliver and George split the bag with candies on merit in the ratio 1:6:3. How many candies should each get if in bag were 210? - Shadow and light

Nine meters height poplar tree has a shadow 16.2 meters long. How long shadow have at the same time Joe if he is 1,4m tall? - Pipes

Water pipe has a cross-section 1939 cm^{2.}An hour has passed 567 m^{3}of water. How much water flows through the pipe with cross-section 300 cm^{2}per 14 hours if water flow same speed? - Server

Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%. - Cyclist

Cyclist goes uphill 1 km for 6.3 minutes and downhill minutes for 2.1 minutes, both applied to the pedals same force. How long he pass 1 km by plane? - Pediatrician

Pediatrician this month of 21 working days takes 3 days holidays. What is the probability that on Monday will be at work? - Radians

Convert 54° to radians. Write result as multiple of number π. - Train and car

The train and the car started at a constant speed to journey. When the train travels 78 km, the car travels 64 km. How many km travels the train when the car travels 78 km? - Scale

Swimming pool is long 110 m and 30 m wide. The plan of the city is shown as a rectangle with area 13200 cm^{2.}What scale is the city plan? - Tmp workers

Three temporary workers cleaned 60 m of walkway in 5 hours. How many meters of the walkway cleared seven volunteers for eight hours? - Gear

Two gears, fit into each other, has transfer 1:5. Centres of gears are spaced 28 cm. What are the radii of the gears? - Copy typist

Typist for 12 hours rewritten 15% of the manuscript. After how many hours he will done 35% of the manuscript? - Pool

If water flows into the pool by two inlets, fill the whole for 9 hours. First inlet filled pool 8 hour longer than second. How long pool is filled with two inlets separately?

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.