Time - problems - page 20

1. Alarm clock
The old watchmaker has a special digital alarm in its collection that rings whenever the sum of digits of the alarm is equal to 21. Find out when the alarm clock will ring. What is their number? List all options ...
2. Steamer
At 6 hours 40 minutes steamer sailed from the port at speed 12 km/h. At exactly 10 hours started sail motorboat at speed 42 km/h. When motorboat will catch steamer?
3. Pumps A and B
Pump A fill the tank for 12 minutes, pump B for 24 minutes. How long will take to fill the tank if he is only three minutes works A and then both pumps A and B?
4. Timeage
Seven times of my age is 8 less than the largest two-digit number. How old I am?
5. Bus lines
Buses connections are started from bus stop on its regular circuit as follows: No. 27 bus every 27 minutes and No.18 every half hour. What time started this two bus lines run if the bus stop met at 10:15 am.?
6. Kangaroo
Kangaroo do 10 jumps in 1 minute and then three minutes lie , then will make 10 jumps in 1 minute and 3 minutes lie, and so on. Find the shortest time in which kangaroo do 30 jumps.
7. Dwarfs
Four dwarfs would prepare firewood for Snow White in580 minutes. After an hour and a half they recruit friends so that finished preparing the wood for 280 minutes. How many dwarfs they recruited?
8. Mr and Mrs
Mr. Calda and Mrs. Cald have a total of 139 years. How many years have when we know that Mr. Calda is 9 years older than Mrs. Cald
9. Father and son
Father is 44 years old, his son 16 years. Determine how many years ago was the father five times older than the son.
10. Grass
Peter and Stano lawn grass for 3 hours 12 minutes. How long would it take to Peter if Stano lawn grass himself for 384 minutes.
11. Aunt
Annie aunt is 35 years old, Annie is 14 years. For how many years will aunt have twice as many years as Annie?
12. Midnight
How many hours are, if the time that elapsed since 8:00 is 2/5 of the time that will past till midnight?
13. Principal and interest
Peter put € 270 principal into bank and at the end of the year on account was € 282. To what annual interest rate that Peter had deposited money in the bank?
14. Charles Bridge
Charles Bridge was 15 times older than Frantův bridge from 1900 in 1931. How old is the Charles Bridge?
15. Blueberries 2
Lenka and Martin collected eight liters of blueberries in two hours. How long will take to collect blueberries by Lenka itself, if we know that she collect all 2.5 hours less than Martin?
16. Two planes
Two planes flying from airports A and B, 420 km distant against each other. Plane from A took off 15 minutes later and flies at an average speed of 40 km/h higher than the plane from B. Determine the average speed of this two aircraft if you know that it
17. Cycling trip
At 8 am started a group of children from the camp to day cycling trip. After 9:00 weather deteriorated sharply and the leader decided to send for the children bus on the same route, which started at 10 hours. For how long and at what distance from the camp
18. Tank
How many minutes does it take to fill the tank to 25 cubic meters of water filled 150hl per hour?
19. 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?
20. Nightingale
Nightingale sang five seconds for 5 hours and 5 minutes. How many seconds were missing to sing 10 hours?

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