Inverse relationship + direct relationship - math problems
Number of problems found: 105
If I read 15 pages a day, I will read the whole book in 18 days. How long will it take to read a book if I only read 9 pages every day?
From 40 liters of milk is produced 8 kg of cheese how many liters of milk are needed to produce 2 kg of cheese?
- Six students
Two pupils painted the class in four hours. How long will it take for six pupils?
The money - coins are minted from the hardest bronze, which contains copper and tin in a ratio of 41: 9. How much copper and tin are in 2kg of bronze money?
- The bakery
The bakery baked 325 cakes from 25kg flour. How many kg of flour do they need to bake 195 pieces of such cakes?
5 children collect 4 liters of blueberries in 1.5 hours. a) How many minutes do 3 children take 2 liters of blueberries? b) How many liters of blueberries will be taken by 8 children in 3 hours?
- Sugar production
From 1 ton of beet, 150 kg of sugar is produced. To clean 1 ton of sugar 450 kg of lime is consumed. Calculate how many kgs of lime is consumed when processing 1 ton of sugar beet?
- A truck 2
A truck leaves home with building materials and makes a return trip every six days. To deliver all the materials, you need eight truck trips every month. How many trucks do you need?
- Book reading
Susan thought, "If I read 15 pages a day, I will read the whole book in 8 days. “How many pages would she have to read a day if she wanted to finish the book on the 6th day from the start of reading? And how many pages does the book have?
- Trio ratio
Hans, Alena and Thomas have a total of 740 USD. Hans and Alena split in the ratio 5: 6 and Alena and Thomas in the ratio 4: 5. How much will everyone get?
- Worker's performance
15 workers paint 180 m fence in 3 days. In how many days will 9 workers paint a 360 m fence? We assume that each worker have the same, constant and unchangeable performance.
In a local supermarket, 3/5 kilogram of squid costs 156.00. How do 4 kilograms of squid cost?
- Five inlets
The tank can be filled with five equally powerful inlets. If the tank is filled by four of these inlets, it takes a total of 30 minutes to fill one-third of the tank. How many minutes does it take to fill an empty tank if it is filled with all five inlets
- Five pumps
The water tank is filled with two pumps in 48 minutes. How long would it take to fill it with 5 same pumps?
- A lot of hay
Martin's grandfather weighed a lot of hay and calculated that for 15 rabbits it last in 100 days. How many days will this lot be enough for 25 rabbits?
- Tennis balls
Can of tennis balls contains 3 balls per can and cost $7 how much will it cost for 36 tennis balls?
Both the shoemaker and his apprentice repaired his shoes. The apprentice worked for 6 days and repaired 10 pairs of shoes every day. The shoemaker did the same job in 4 days. How many pairs of shoes did the shoemaker repair per day?
Ten painters paint the school in 20 days. How many days do four painters paint the school at the same pace of work?
- The farmer
The farmer calculated that the supply of fodder for his 20 cows was enough for 60 days. He decided to sell 2 cows and a third of the feed. How long will the feed for the rest of the peasant's herd last?
- Coils of transformer
The primary coil of the transformer has 400 turns, a current of 1.5 A passes through it and is connected to a voltage of 220 V. For the secondary coil, find the voltage, current, and a number of turns if the transformation ratio k = 0.1.