# Examples for 8th grade - page 4

- Tractors

Fields go plow two tractors with various performance. The first tractor plow whole field in 5 hours, the second tractor plow whole field 5 hours longer. How long take plow whole field with two tractors? - Segments

Which of the pairs of numbers on the number line encloses the longest segment: ? - Drunk man

Drunkman has 2.1‰ of alcohol in the blood. How many grams of alcohol has in blood, if he have 6 kg of blood? - Seedcake

Seedcake costs 50 cents. How many minimum seedcakes we must buy that we can pay in cash only whole euros? - Mr Novak

Mr Novak earns an average 638 euros. When increasing the salary they gave him a choice: ? What is better choice for Mr Novak? - Time

Write time in minutes rounded to one decimal place: 1 h 42 m 22 s. - Density - simple example

Material of density of 1278 kg/m^{3}occupies a container volume of 80 cm^{3}. What is its mass? - 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? - Railways

Railways climb 5.8 ‰. Calculate the height difference between two points on the railway distant 2389 meters. - Vinegar 2

How many percentage of getvinegar solution, if we mix to 14.5 liters of 7.8% and 2.5 liters of 5.8% vinegar? - Sprayers

The vineyard can be sprayed first sprayer in 5 hours and with the second in 7 hours. How long would it take if we use sprayers both at once? - Monkey

Monkey fell in 31 m deep well. Every day her scramble 3 meters, at night dropped back by 2 m. On that day it gets hangover from the well? - Tournament

Determine how many ways can be chosen four representatives from 27 students to school tournament. - Pizza master

Master says that he can splits pizza to 16 parts by five equals straight cuts. Is it possible? - Discount

Ladies sweater was twice discounted. First by 17%, then by 17% of the new price. Its final price was 72 USD. Determine the original price of sweater. - Team

The football team has 11 players. Their average age is 21 years. During the match due to injury, one player withdraws and the average age of the team is 20. How old was injured player? - Tractors

6 tractors started plowing the field that them together take 12 days. Agronomist hesitates to A) after 2 days to withdraw 2 tractors, or B) after 3 days to withdraw 3 tractors. Help him which of these two cases will be plowing done sooner. - Cube diagonal

Determine length of the cube diagonal with edge 91 dm. - Exam average

Average of marks that have on the certificates students of 8.A class in mathematics is exactly 2.45. If we did not add 1 and 3 of sutdents Michael and Alena, who arrived a month ago, it would average exactly 2.5. Determine how many students have class 8. - Square diagonal

Calculate length of the square diagonal if the perimeter is 200 cm.

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