Maths practice for 14 year olds - page 71 of 369

Number of problems found: 7380

Natural numbers
Find the number of all natural numbers greater than 200 in which the digits 1, 2, 4, 6, 8 occur at most once and not contains any other digits.
RT area
A right triangle has an area of 54cm². Calculate the sizes of both legs if the shorter leg is 75% of the size of the longer leg.
Distances 79974
The picture shows three villages, A, B, and C, and their mutual air distances. The new straight railway line is to be built so that all the villages are the same distance from the line and that this distance is the smallest possible. How far will they be
A chemist
A chemist recorded the change in temperature of a cooling liquid as −25.5° over a 1.5-minute period. The temperature fell at a constant rate. What was the rate of change in temperature? Enter your answer in the box. °F per minute
Hypotenuse 79904
I have a right triangle, the length of the hypotenuse is c 20, and I only know the side ratio a:b = 2:1. I can't figure out the actual length of the hangers = I'm already an old man, and my brain doesn't work at 100% like it did years ago at school - I co
Right-angled 79894
Mug's handle is in the shape of a right-angled triangle with a hypotenuse of 15.8 cm and a shorter overhang of 5 cm. How tall is a mug?
Distance 79874
The mast is 190m high and is attached to six ropes which are anchored in the ground at a distance of 20m from the base of the mast. How many meters of rope were needed?
Determine 79864
Determine by how many meters the deviated tower, whose height is 56m, and the top of the tower is located at 55.855m.
The average 8
The average point per game in NCAA men's basketball is 71 points. If Duke scored 112% of the average and UNC scored 0.87 times the average, who scored more points?
Parallelogram - sides
A parallelogram has a perimeter of 30 cm and heights of 10 cm and 6 cm. Find the lengths of its sides.
Repeated 79734
How many numbers a) less than 500, b) greater than 500 can be formed from the digit 0,1,5,8,9 so that no digit is repeated?
Different 79704
Thirty-two boys and 34 girls came to the dance. How many different dance pairs can they make, given that each team is given: they can only dance for 1 minute and then take turns in 5 seconds? Calculate how long the dance evening would last for all the pai
Determine 79634
There are 12 apples and 10 pears in the basket. Peter has to choose either an apple or a pear from them so that Víra, who chooses 1 apple and 1 pear after him, has the greatest possible choice. Determine what Peter chooses.
Determine 79604
In the shoe cabinet, there is one pair each of boots, sandals, tennis shoes, and brown and black ankle boots. Determine how many ways one right shoe and one left shoe can be chosen from among them that do not belong together.
T-shirts
The team bought white t-shirts for CZK 100/piece and black t-shirts for CZK 80/piece. A total of 50 pieces for 4200 CZK. How many black and white T-shirts did they buy?
Supermarket 79504
The supermarket reduced the original price of the skis by 20% in January. At the beginning of February, they reduced the new price by another 29%. By what percentage were the skis' costs lower than the original price in February?
A test 3
A test of five light bulbs showed that they burned for the following lengths of time (in days): 17 2/3, 19 1/4, 20 1/2, 21, and 18 3/4. For how many days, on average, did the light bulbs burn?
Temperature 79404
The aluminum coil line has a resistance of 4.6 Ohm at an elevated temperature of 64°C. At what base temperature will the resistance be 2 ohms?
General triangle
Given a general triangle ABC. Its perimeter is 30 cm, with side a=2 cm longer than side b and 5 cm shorter than side c. Determine the area of the triangle.
Yesterday 79344
Petr played Minecraft for 2 hours yesterday. Pavel played 10% longer. How many minutes did Pavel play?

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