# Examples for 8th grade - page 84

- Class

In a class are 32 pupils. Of these are 8 boys. What percentage of girls are in the class? - Unknown number 4

I think number. When I divided its square root by its 1/9, I get a number 1. What number am I thinking? - Workers

Group of workers washing half of the windows of the building in two hours. How long will take half the workers wash all the windows of the building? - Three monks

Three medieval monks has task to copy 600 pages of the Bible. One rewrites in three days 1 page, second in 2 days 3 pages and a third in 4 days 2 sides. Calculate for how many days and what day the monks will have copied whole Bible when they begin Wednesd - Backpack

Large backpack cost CZK 1352, little is 35% cheaper. How much we paid for 5 large and 2 small backpacks? - Outer contact of circles

Construct a circle k1 (S1; 1.5 cm), k2 (S2; 2 cm), and K3 (S3; 2.5 cm) so that they are always two outer contact. Calculate the perimeter of the triangle S_{1}S_{2}S_{3}. - Ladder

Ladder 10 meters long is staying against the wall so that its bottom edge is 6 meters away from the wall. What height reaches ladder? - Rectangle

Find the dimensions of the rectangle, whose perimeter is 108 cm and the length is 25% larger than the width. - Trees

A certain species of tree grows an average of 0.5 cm per week. Write an equation for the sequence that represents the weekly height of this tree in centimeters if the measurements begin when the tree is 200 centimeters tall. - Sale off

Product cost 95 euros before sale off. After sale off cost 74 euros and 10 cents. About what percentage of produt became cheaper? - Land areas

Two land areas is 244 m^{2}. The first parcel is 40 m^{2}less than twice of the second one. What have acreage of each parcel? - Rectangle

The length of the rectangle is 12 cm greater than 3 times its width. What dimensions and area this rectangle has if ts circumference is 104 cm. - Money

Peter has 2x more money than Michael. But if Peter gave Michael € 16 Michael would have 3.5 times more money than Peter. Determine how much money was originally Peter and how much Michael. - Summer camp

Out of the 180 students at a summer camp, 72 signed up for canoeing. There were 23 students who signed up for trekking, and 13 of those students also signed up for canoeing. Use a two-way table to organize the information and answer the following questio - Baskets of apples

Grandfather gathered apples into baskets. He filled one large and three small baskets. Small baskets are identical and each can hold 3 kg of apples less than in a large basket. In small baskets together 3 kg of apples over a large basket. How many kilogram - VAT on books

The cost of a book in the store is 12.5 euros. How much euros is the VAT of this book? VAT is 10%. - Pyramid

The pyramid has a base rectangle with a = 6cm, b = 8cm. The side edges are the same and their length = 12.5 cm. Calculate the surface of the pyramid. - Central park in city

The city park has the shape of a rectangle of 180 meters in length and 120 meters in width. People make their walk through the center of the park from one corner to the second. Calculate how many meters this way is shorter than they walked along the path. - Distilled water

Sea water contains 5% salt. How many distilled water should be pour to 40 kg of sea water so that the salt content is 2%. How many kilograms of 2% of sea water we get? - Sides of triangle

Triangle has circumference 42 cm. Side a is 2 times shorter than side b and sice c is 2 cm longer than side a. Determine the sizes of sides of a triangle.

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