System of equations - 8th grade (13y) - math problems
Number of problems found: 436
- Father and son
When I was eight years old, my father was 30 years old. Today, my father is 3 times more than me. How old am I?
- Railway embankment
The section of the railway embankment is an isosceles trapezoid, the sizes of the bases of which are in the ratio 5: 3. The arms have a length of 5 m and the height of the embankment is 4.8 m. Calculates the size of the embankment section area.
- A bottle
A bottle full of cola weighs 1,320 g. If we drink three-tenths of it, it will weigh 1,008g. How much does an empty bottle weigh?
- Aunt Rose
Aunt Rose gave $2500 to Mani and Cindy. Mani received $500 more than Cindy. How mich did Cindy received?
- Side lengths
In the triangle ABC, the height to the side a is 6cm. The height to side b is equal to 9 cm. Side "a" is 4 cm longer than side "b". Calculate the side lengths a, b.
- 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?
- Bike ride
Marek rode a bike ride. In an hour, John followed him on the same route by car, at an average speed of 72 km/h, and in 20 minutes he drove him. Will he determine the length of the way that Marek took before John caught up with him, and at what speed did M
- When I
When I am as old as my older brother is today, my brother will be twice as old as I am today. a) How old is my brother if I am 8 years old today? b) How old am I if my brother is 21 today?
In the confectionery, the price for 1 kg of pistachio candies cost CZK 360, and the price for 1 kg of hazelnut candies was CZK 280. Mixing these two types of sweets created a box of chocolates. How many grams of pistachios and how many grams of hazelnut c
- The dormitory
The dormitory accommodates 150 pupils in 42 rooms, some of which are triple and some are quadruple. Determine how many rooms are triple and how many quadruples.
Men's shirt has sewn 9 buttons and blouse 3 buttons. Together they sewed 60 pieces and consumed 390 buttons. How many shirts?
- Two accounts
Two accounts in the bank, one per year interest 2%, the second 3%. Total interest income 1900 USD. If interest rates were reversed, the yield would be USD 200 higher. What are the amounts on each account?
- Sow barley
Farmers wanted to sow barley within 13 days. Due to the excellent weather, they managed to exceed the daily plan of sowing by 2 ha and therefore finished sow grain in 12 days. How many hectares of land did they sow with barley?
- Jane plants
Jane plants flowers in the garden. If she planted 12 every hour instead of 9 flowers, she would finish with the job an hour earlier. How many flowers does she plant?
- In the classroom
There are 30 boys and a few girls in the class. In the six months, 28 boys and all girls benefited, which was 95% of all pupils. How many pupils are there in the classroom?
- Twelve ties
The price of 12 ties before the discount was the same as 15 ties after discount. Calculate the price of 1 tie after discount, if you know that the discount price of one tie fell by 40 CZK?
- Three brothers
The three brothers have a total of 42 years. Jan is five years younger than Peter and Peter is 2 years younger than Michael. How many years has each of them?
- Two numbers
The difference between the two numbers is 74. If we divide a larger number by a smaller one, we get a quotient 7 and the rest of 2. Determine both numbers.
- 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
- Two melons
There are 2 melons in the box. Together they weigh 11kg. The weight of green is 3 kg less than three times the weight of yellow. What is the weight of a green melon?
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