Math practice for 13 year olds - page 282 of 424

Number of problems found: 8474

A boy
A boy of 1.7m in height is standing 30m away from the flagstaff on the same level ground. He observes that the angle of deviation of the top of the flagstaff is 30 degrees. Calculate the height of the flagstaff.
Rectangles 6279
Reduce the dimensions of the rectangle with dimensions of 21 cm and 3 dm in a ratio of 4:6. In what proportion will the areas of both rectangles be?
Birthday 6277
Peter got a new bike for his birthday. His bike was equipped with many gears. How many gear options does Peter have if you have three wheels at the front and eight wheels at the back? List them all
Block-shaped 6276
288hl of water was filled into a block-shaped tank with bottom dimensions of 12 m and 6 m and a depth of 2 m. What percentage of the volume of the tank did the water occupy?
Simultaneously 6272
The first inflow fills the tank in 4 hours and the second tributary in 6 hours. How long will it take to fill both tributaries simultaneously, but the species will start an hour later?
Calculate 6268
Calculate the unknown velocity x if: 24 km/h. ... . .. .20min x km/h. ... . .. .12min
Production 6266
They produced a total of 7,290 light bulbs in three workshops. How much did each workshop produce when we write their production in the ratio of 2:3:4
Dimensions 6264
Calculate the length of the body diagonal of a block whose dimensions are a = 5cm, b = 6cm, c = 10cm.
A regular
A regular triangular prism with a base edge of 20 dm and a height of 30 dm is drawn. Find the volume of the prism and the area of the shell.
Discounted 6258
The women's sweater was discounted twice. First 10% later by 10% of the new price, its final price was 324 CZK. Determine the price of the sweater.
Exchanged 6256
Pupils exchanged pencils, erasers, and pens so that there were two pens for 15 pencils and three pencils for two erasers. How many erasers were there for one pen?
Perimeter 6254
Perimeter and area of the rectangle. Diagonal 260m and one side 150m
Diamond diagonals
Calculate the diamonds' diagonal lengths if the diamond area is 156 cm square and the side length is 13 cm.
Shadow of tree
Miro stands under a tree and watches its shadow and shadow of the tree. Miro is 180 cm tall, and its shade is 1.5 m long. The tree's shadow is three times as long as Miro's shadow. How tall is the tree in meters?
Right angled triangle 3
Side b = 1.5, hypotenuse angle A = 70 degrees, Angle B = 20 degrees. Find the length of its unknown sides.
Soaps
Each box has the same number of soaps. A quarter of all boxes contain only white soaps, and in each of the remaining 120 boxes, there are always half the white soaps and half the green. White soaps total 1200. (a) the number of all soap boxes; (b) the sma
Two equations
Solve equations (use adding and subtracting of linear equations): -4x+11y=5 6x-11y=-5
Product - price
The original price of the product was 6,300. We reduced the product price by 10 percent twice. What is its final price?
Sunflower 6230
Jana and Danka had a total of 125 sunflower seeds. When eating, Jana was smarter and ate 13 more seeds. They gave the last 6 seeds to the parrot. How many seeds did Jane eat, and how many did Dan eat?
Three 43
Three brothers inherited a cash amount of 62,000 and divided it among themselves in the ratio of 5:4:1. How much more is the largest share than the smallest share?

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