# 8th grade (13y) + direct relationship - examples

- Shadow of tree

Miro stands under a tree and watching its shadow and shadow of the tree. Miro is 180 cm tall and its shade is 1.5 m long. The shadow of the tree is three times as long as Miro's shadow. How tall is the tree in meters? - 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? - Cuboid

The sum of the lengths of the three edges of the cuboid that originate from one vertex is 210 cm. Edge length ratio is 7: 5: 3. Calculate the length of the edges. - Line segment

The 4 cm long line segment is enlarged in the ratio of 5/2. How many centimeters will measure the new line segment? - 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 trapezoid area. - Five pumps

The water tank is filled with two pumps in 48 minutes. How long would it take to fill it with 5 same pumps? - Pool

If water flows into the pool by two inlets, fill the whole for 18 hours. First inlet filled pool 10 hour longer than second. How long pool is filled with two inlets separately? - Forestry workers

In the forest is employed 64 laborers planting trees in nurseries. For 8 hour work day would end job in 35 days. After 12 days, 20 laborers go forth. How many days is needed to complete a planting trees in nurseries by others, if they will work 9 hours a - Bonus

Gross wage was 1430 USD including 23% bonus. How many USD were bonuses? - Excavation

Mr. Billy calculated that excavation for a water connection dig for 12 days. His friend would take 10 days. Billy worked 3 days alone. Then his friend came to help and started on the other end. On what day since the beginning of excavation they met? - Beer

After three 10° beers consumed in a short time there are 6.2 g of alcohol in 5 kg adult human blood. How much is it per mille? - Coffee

In stock are three kinds of branded coffee prices: I. kind......6.9 USD/kg II. kind......8.1 USD/kg III. kind.....10 USD/kg Mixing these three species in the ratio 8:6:3 create a mixture. What will be the price of 1100 grams of this mixture? - Server

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

The cuboid has a surface area 7086 cm^{2,}the length of its edges are in the ratio 4:2:1. Calculate the volume of the cuboid. - Gimli Glider

Aircraft Boeing 767 lose both engines at 45000 feet. The plane captain maintain optimum gliding conditions. Every minute, lose 1870 feet and maintain constant speed 212 knots. Calculate how long takes to plane from engines failure to hit ground. Calculate - Scale

Swimming pool is long 110 m and 30 m wide. The plan of the city is shown as a rectangle with area 8.25 cm^{2.}What scale is the city plan? - ŽSR

Calculate fixed annual personnel costs of operating monorail line 118 km long if every 5 km is station, which serve three people - one dispatcher and two switchman in 4-shift operation. Consider the average salary of the employee 885 €. - Cyclist

Cyclist goes uphill 10 km for 50 minutes and downhill minutes for 29 minutes, both applied to the pedals same force. How long he pass 10 km by plane? - Engineer Kažimír

The difference between politicians-demagogues and reasonable person with at least primary education beautifully illustrated by the TV show example. "Engineer" Kažimír says that during their tenure there was a large decline in the price of natural gas, pri - Road repair

Road repair took 10 days for 36 workers if they worked 9 hours a day. How many days take repair same road 37 workers if they work 8 per day?

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