Time + natural numbers - practice problems
Number of problems found: 116
- Human population
The populations of two cities after t years can be modeled by -150t+50,000 and 50t+75,000. What is the difference in the populations of the towns when t=4? - Planetary system
Robert has built a mechanical model solar system with three balls representing planets at the end of rods. Each rod is attached to the center, representing the Sun. The planets are lined up when he turns on the motor. The innermost planet makes a revoluti - Library 4
Library A has a total collection of 250 books. Library B has 100 more books than Library A, and Library C has twice as many books as the combined number of books in Library A and B. What is the total number of books in libraries A, B and C? - Fransisca
Fransisca read a book 391 pages long, reading 17 pages a day. There are two more books in the series. How long will it take Fransisca to read all three books if they have the same page length and she reads at the same speed?
- Ronald 2
Ronald and Tim both did their laundry today. Ronald does laundry every 6 days, and Tim does laundry every 9 days. How many days will it be until Ronald and Tim both do laundry on the same day? - Hans spent
Hans spent three days baking 224 cookies. On the second day, he baked twice as many as he did on the first day. On the third day, he baked half as many as he did on the first day. Which equation represents the situation if x is the number of cookies Hans - Hourglass 83292
The hourglass ticks three times in 5 minutes. How many times do they spill in 2 hours? - Composition 83241
You have to create as many identical candy boxes as possible from 280 orris, 252 nougat, and 420 marzipan candies. At the same time, you must not have any candy left or missing. What will be the composition of one box of chocolates, and how many candies w - Condition 83228
Three boys, Ivo, Vlado, and Alan, are reading the same book, with the condition that they will read the same number of pages every day during the entire reading until they finish the book. Ivo reads 18 pages from it every day, Vlado reads 24 pages, and Al
- Morning 82968
The new truck makes one trip with sand in 18 minutes, and the older truck takes one-third as long to make one trip. Both will leave at the same time in the morning. How long will it take for them to meet again, and how many times will they meet in an eigh - Strawberries 82738
Three classmates worked part-time during the summer vacation harvesting strawberries. Jan collected 145 baskets of strawberries during the entire time of the brigade. Peter collected 185 baskets. How many baskets did their classmate Stan collect, if we kn - Calculate: 80736
Gaius Julius Caesar was born in 100 BC. He was murdered when he was 56 years old. Calculate: a) in what year was he murdered? b) How many years ago was he born? c) How many years ago did he die? - Simultaneously 80392
Dulikovci, Elikovci, Filikovci, and Galikovci visited each other often last month. Each family visited each family exactly once. How many visits did all four families make together? If two families came to visit one family simultaneously, count it twice. - Tablets 80294
Pepík is sick and has to take 1 tablet three times a day. How many days will a pack of 30 tablets last him if he only takes 1 tablet in the morning and evening every third day?
- Schoolyard 79854
The children ran the school relay four times around the schoolyard. The shortest measured time was 2 minutes, and the longest was 3 minutes. In what was the longest and shortest time could the relay run around the yard? - Yesterday 79344
Petr played Minecraft for 2 hours yesterday. Pavel played 10% longer. How many minutes did Pavel play? - Situation 78694
There is a geyser and a volcano in a nature reserve in Iceland. The geyser erupts regularly every 18 days, and clouds of smoke rise from the volcano every 40 days. how many times in the course of 9000 days will there be a situation where we can observe bo - Steamers 67804
Two steamers set out on a voyage from the same port. The first steamer returns to port every fourth day, and the second steamer returns every fifth. How many days do they meet again? - Beginning 66104
The kangaroo always jumps three steps up. Each time he jumps, the bunny jumps down two steps. On which stairs will they meet? The kangaroo stands on the 1st step at the beginning and the bunny on the 100th.
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