Math practice for 13 year olds - page 139 of 414

Number of problems found: 8275

The ratio
The ratio of the lengths of the two circles is 5:2. Find the ratio of a a) the radii of these circles b) the areas for these circles
The cost 4
The cost to tile a floor that measures 7 x 6 square feet is $ 2,100. How much will tile a floor measuring 11 x 13 square feet cost?
Last wagon
A 200 m long train passes through the 700 m long tunnel so that a time of 1 minute elapses from the entry of the locomotive into the tunnel to the exit of the last wagon from the tunnel. Find the speed of the train.
Grandma
Grandma is 57 years older than her two twin granddaughters. If we add the ages of an older woman with both granddaughters, we get the number 99. How old is her old woman?
Circular segment
Calculate the radius and area of the circular segment if the center angle = 106° and the length of the corresponding circular arc is l = 52 cm.
Circular arc
Calculate the center angle and length of the circular arc if the radius r = 21 cm and the area of the slice is 328.5 cm²
Quadrilateral in circle
A quadrilateral is inscribed in the circle. Its vertices divide the circle in a ratio of 1:2:3:4. Find the sizes of its interior angles.
Volleyball 2
In a volleyball game, Michael made four shots in 8 tries. At this rate, how many shots can he make in 12 tries?
Three-leggers
On a newly discovered planet live animals that astronauts named after the number of legs one-leggers, two-leggers, three-leggers, and so on (there were no animals without legs there). Animals with an odd number of legs have two heads, animals with an even
Circular segment
What is the radius of a circular section whose central angle is 36° and the area of S = 53.095 cm²?
Circle segment
A quarter circle with a radius of 4 has the same area as a circle segment with a radius of 3. What is the magnitude of the center angle of the circle segment?
Circular segment
Calculate the area of a circular segment if the radius r = 80 cm and the central angle is α = 110°.
The number - digits
Vera formed different three-digit numbers from three given digits. When she added up all these numbers, the sum was 1554. What digits did Vera use?
Round table
Find the number of ways in which eight people can be seated at a round table such that 2 of them always sit together.
Adult
Adult tickets for a puppet show sell at P125.05 and children at P99.35. If 25 parents and 70 children watched that show, how much did the show earn?
Two expressions
When x = 3 and y = 5, how much does the value of 3x² – 2y exceed the value of 2x² – 3y?
Excavation digging days
The workers dug one-quarter of the excavation on the first day, half the rest on the second day, and the remaining 15 m on the third day. How many meters did they dig on the first and second day?
Gold tin alloy
To make a gold decorative item, we alloy 250 g of 18-carat and 200 g of 14-carat gold with tin. How much tin must be added to obtain 14.6-carat gold? Express the purity of the obtained gold in the sense of the applicable legislation.
Three in ratio
1/8 of the balls in a bag are red, 5/8 are blue, and the rest are green. Find the ratio of red to blue to green balls.
Silvia
Silvia is 20% lighter than Katy. What percentage is Katy heavier?

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