Examples for 8th grade - page 26
- Cuboid aquarium
Cuboid 25 times 30 cm. How long is third side if cuboid contains 30 liters of water?
Less than 20 children is played various games on the yard. They can create a pairs, triso and quartets. How many children were in the yard when Annie came to them?
One half of rope use Mam for packaging, half of the rest got son, half of the rest he took father and two fifths of what remained, got daughter. Remained 52 cm of rope. How long was rope at the beginning?
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?
In the front row sitting three students and in every other row 11 students more than the previous row. Determine how many students are in the room when the room is 9 lines, and determine how many students are in the seventh row.
- Three ints
The sum of three consecutive integers is 2016. What numbers are they?
Four pupils is going via dark hall. Start at one side and have to get to the other side for 17 minutes. They have only one lamp for the trip. The corridor is narrow, they can therefore go up two pupils at a time and go at the slower speed. Each pupil went.
- Classs mean
Class size is 30 students, math was not worse than sign 2. Determine the number of pupils who were sign 1 if the class had a 1.4 sign average.
- Sales off
Goods is worth € 31 and the price of goods fell two weeks in a row by 10%. How many % decreased overall?
- Ski class
Class attend 30 boys and some number of girls. Ski training was attended by 28 boys and all the girls, which was 95% of all students. How many girls attend this class? How many percent is that?
- Cuboids in cube
How many cuboids with dimensions of 6 cm, 8 cm and 12 cm can fit into a cube with side 96 centimeters?
A one-third of unknown number is equal to five times as great as the difference of the same unknown number and number 28. Determine the unknown number.
- 7 roses
Peter buys 7 roses. When he pay for it left him 4 euro. If he bought 5 roses left him 40 euros. How many euros had Peter before buying?
- Bonbons 2
Kilo sweets will cost 260 CZK. The first type has a price per 320 kg, the second type 240 CZK per kg. How many kilos of both kinds of sweets need to prepare a 77 kg mixture ?
- Plan of the village
Plan of the municipality in 1:1000 scale has plotted garden with dimensions 25 mm and 28 mm. Determine the area of gardens in ares in reality.
- Rhombus diagonal
Area of rhombus is 417. One diagonal measures 45, find length of other diagonal.
Fresh mushrooms contain 96% water, dried 12%. How many kg of fresh mushrooms is needed to collect to get 7 kg dried?
We will throw two dice. What is the probability that the ratio between numbers on first and second dice will be 1:2?
- IS trapezoid
Calculate the length of diagonal u and height v of isosceles trapezoid ABCD, whose bases have lengths a = |AB| = 26 cm, c = |CD| = 5 cm and legs b = d = |BC| = |AD| = 19 cm.
The elections attended a total 4436 voters. First day 32 men more than women, the second day 38 women more than men. How many women attended elections?