# Latest problems - page 24

1. Five pupils Five pupils clean 30 chairs one hour before four pupils. How many chairs clean one pupil in 1 hour?
2. There There are 32 trees of three species in the orchard. 25% cherries, three eighty pears, others plums. How many plums are in the orchard?
3. Diagonals of pentagon Calculate the diagonal length of the regular pentagon: a) inscribed in a circle of radius 12dm; b) a circumscribed circle with a radius of 12dm.
4. Sss triangle Calculate the area and heights in the triangle ABC by sides a = 8cm, b = 11cm, c = 12cm
5. Dance ensemble The dance ensemble took the stage in pairs. During dancing, the dancers gradually formed groups of four, six and nine. How many dancers have an ensemble?
6. The tourist The tourist traveled 190km in 5 hours. Part of the journey passed at 5 km/h. The rest he went by bus at a speed of 60 km/h. How long has a bus gone?
7. On the trip On the trip were more than 55 children, but less than 65 children. Groups of 7 could be formed, but groups of 8 no. How many children were on a trip?
8. The quotient The quotient of g and 55 is the same as 279. What is g?
9. Linear system Solve a set of two equations of two unknowns: 1.5x+1.2y=0.6 0.8x-0.2y=2
10. Pavement Calculate the length of the pavement that runs through a circular square with a diameter of 40 m if distance the pavement from the center is 15 m.
11. The cube The cube has an edge of 12 dm. The second cube has an edge exactly 20% longer. How many % is more water in the second cube than in the first cube, if the first cube is full to 3/4 and the second to 3/8?
12. Exchange rates If the Canadian dollar appreciated by C\$0.005 relative to the US dollar, what would be the new value of the Canadian dollar per US dollar? Assume the current exchange rate was US\$1 = C\$0.907.
13. Two thirds Find two-thirds of the number equal to two-thirds of 99
14. Clock's gears In the clock machine, three gears fit together. The largest has 168 teeth, the middle 90 teeth, and the smallest 48 teeth. The middle wheel turns around its axis in 90 seconds. How many times during the day do all the gears meet in the starting position?
15. Double 5 Peter was thinking of a number. Peter doubles it and gets an answer of 8.6. What was the original number?
16. Find the 6 Find the total cost of 10 computers at \$ 2100 each and 7 boxes of diskettes at \$12 each
17. Tickets On Monday, 33 tickets were sold. Every next day, twice as many as the previous day. How many tickets were sold on Friday and how many totally from Monday to Friday?
18. Composite ratio Jakub, Aneta, and Lenka divided 1342 USD in the ratio 5/2: 3/10: 1/4. How much did Lenka take?
19. Two diggers Two diggers should dig a ditch. If each of them worked just one-third of the time that the other digger needs, they'd dig up a 13/18 ditch together. Find the ratio of the performance of this two diggers.
20. Temperature 5 Temperature outside starts at 0 Fahrenheit. Over time the temperature changes at a rate of -0.6 Fahrenheit per hour. How long will it take for the temperature to reach -4.5 Fahrenheit?

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