Direct relationship - 7th grade (12y) - math problems
Brass is an alloy of copper and zinc in a ratio of 3: 2. How many grams does a component that required 270 g of copper weigh?
- 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?
- A bucket
A bucket has 4 liters of water in it when it is 2/5 full. How much can it hold?
- The orchard
4 temporary workers harvested the orchard in 9 days. How many temporary workers we need for six days?
- 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?
- 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?
- A filter
It is a pool with a volume of 3500 liters. The filter filters at 4m cubic per hour. How many minutes would it filter the entire pool?
- Eight masons
Eight masons will plaster a wall with an area of 1440 m2 in 9 days. They work 8 hours a day. How much area will plaster 6 masons in 4 hours?
Ten painters paint the school in 20 days. How many days do four painters paint the school at the same pace of work?
- Proportion 3
For every 8 mango trees in the orchard, there are 4 star apple trees. If there are 1320 trees, how many trees of each kind are there?
- The perimeter 3
The perimeter of a rectangle is 35 cm. The ratio of the length to its width is 3:2. Calculate the dimensions of the rectangle
- A sculptor
A sculptor is duplicating a statue based on an original statue. If the scale factor of the replication is 3.2, will the new statue be larger or smaller than the original statue (enter 1 = larger, 0= smaller)
- Cook on gas
The gas cylinder will last for 30 weekends for 2 hours of daily cooking. How many days will we be able to cook on a new cylinder when we cook 3 hours a day?
- In the
In the national park, the ratio of the wooded area to grassland is 4: 1. The total area is 385km2. What area is wooded?
After the floods, four equally powerful pumps exhausted water from the flooded cellar in 6 hours. How many hours would take a drained out with three equally powerful pumps?
- Hay bags
4 cows eat 16 hay bags in 5 days. How many bags will eat 5 cows in 7 days?
- 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?
Find how many donuts each student will receive if you share 126 donuts in a ratio of 1:5:8
- Composite ratio
Jakub, Aneta, and Lenka divided 1342 USD in the ratio 5/2: 3/10: 1/4. How much did Lenka take?
- Land area 2
A land area was divided among the three heirs in the ratio 5:2:4. If the largest share was 20 hectares of land, what is the total area of land? Please show your solution and what kind of proportion is this please