Examples for 8th grade - page 77

Unknown number
Identify unknown number which 1/5 is 40 greater than one tenth of that number.
Book read
If Petra read 10 pages per day, she would read the book two days earlier than she read 6 pages a day. How many pages does a book have?
Theatro
Theatrical performance was attended by 480 spectators. Women were in the audience 40 more than men and children 60 less than half of adult spectators. How many men, women and children attended a theater performance?
Plum
On the platter are plum. How many were there if its have to be able to share equally among 8,10 and 12 children?
Base, percents, value
Base is 344084 which is 100 %. How many percent is 384177?
Class 9A
On the final certificate have one quarter of the class 9A mark "C" of mathematics, seventh mark "C" from the Czech language and two students failed in chemistry. How many students attend class 9A?
Greenhouse
Garden plastic greenhouse is shaped half cylinder with a diameter of 6 m and base length 20 m. At least how many m² of plastic is need to its cover?
Three figures - numbers
The sum of three numbers, if each is 10% larger than the previous one, is 662. Determine the figures.
Sale off 2
A pair of of blues jeans went on sale. After a 30% reduction the pants cost $35. How much did the jeans cost before the price reduction?
Line segment
Cut a line segment of 15 cm into two line segments so that their lengths are in ratio 2:1. What length will each have?
Candy
The price for 1kg of more expensive candy is 125 CZK. The price for 1kg of cheaper candy is 100 CZK. We make two different blends of candy. And now. The second blend contains 2kg of more expensive candy and several kg of cheaper candy. The price per 1 kg o
Family
Mom is 39 years old. Karl is eight years and Paul 4 years. For many years mother would old just like two children together?
Pumps
Five pumps pumped 1,800 hl of water for 3 hours. How many hectoliters of water pump same two powerful pumps for six hours?
Image scale
The actual image dimensions are 60 cm x 80cm and has a reduced size 3 cm x 4 cm. At what scale the image was reduced?
Trees - orchard
The 3/5 trees are apple trees and 1/3 of the trees are cherries. The remaining 5 trees are pear trees. How many trees are in the orchard.
Four ropes
TV transmitter is anchored at a height of 44 meters by four ropes. Each rope is attached at a distance of 55 meters from the heel of the TV transmitter. Calculate how many meters of rope were used in the construction of the transmitter. At each attachment.
Cableway
Cableway has a length of 1800 m. The horizontal distance between the upper and lower cable car station is 1600 m. Calculate how much meters altitude is higher upper station than the base station.
Contestants
In the competition it was possible to get 0-5 points. In fact, 5 contestants of the 15 best contestants has earned 5 points or 4 points (which have won 10 contestants). The number of contestants who earned 3 points was the same as the number of contestan
Cost reduction
Two MP3 players whose price was equal to originally have been discounted the first by 20%, the second by 35%. After the price reduction was the difference in their prices 750, - CZK. What was the original price of each of the two players?
Family parcels
In father will he divided the land so that the older son had three bigger part than younger son. Later elder son gave 2.5 ha field to younger and they had both the same. Determine the area of family parcel.

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