# How old

The student who asked how many years he answered: "After 10 years I will be twice as old than as I was four years ago. How old is student?

**Result****Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):**

**Showing 1 comment:**

#### To solve this example are needed these knowledge from mathematics:

## Next similar examples:

- The tourist

The tourist came started from the hostel at an average speed of 5km/h. Half an hour later, the bicyclist started along the same route at a speed of 20km/h. How many minutes will a cyclist catch up and how many kilometers will he go? - Workers

Two workers will construct the stage at the festival in 54 hours. Organizers need to shorten the assembly time by 42 hours. How many workers must the assembly company send? - Candy and boxes

We have some number of candy and empty boxes. When we put candies in boxes of ten, there will be 2 candies and 8 empty boxes left, when of eight, there will be 6 candies and 3 boxes left. How many candy and empty boxes left when we put candies in boxes of. - The farmer

The farmer had 140 sheep. For the next year, she decided to change the number of sheep in ratio 10: 7. How many sheep will he have then? - Paul earned

Paul earned 300 Kč in one hour, Václav 1/3 more than Paul. Václav worked 60 hours, which is 1/3 fewer hours than Paul worked. How many percents less earned Paul an hour than Václav? How many hours did Paul more than Václav? How much did Paul earn more t - Solutions, mixtures

How many liters of 70% solution we must add to 5 liters of 30% solution to give us a 60% solution? - Girls

The boys and girls in the class formed without the rest of the fives, 2 girls and 3 boys. There are 6 girls missing to create mixed pairs (1 boy and 1 girl). How many girls are in the classroom? - Speed of car

The car went to a city that was 240 km away. If his speed increased by 8 km/h, it would reach the finish one hour earlier. Determine its original speed. - Taxi

A taxi ride costs $3 plus $2.50 per mile. Write and Graph an equation in two variables that represents the total cost of a taxi ride. - The sides

The sides of a rectangle are in a ratio of 2:3, and its perimeter is 1 1/4 inches. What are the lengths of its side? Draw it. - Alice

Alice spent 5/11 of her money on a back pack. She has $42 dollars left. How much was her back pack? - Ratio of sides

The triangle has a circumference of 21 cm and the length of its sides is in a ratio of 6: 5: 3. Find the length of the longest side of the triangle in cm. - Find radius

Find radius of circle using pythagorean theorem where a=9, b=r, c= 6+r - House numbering

The residential house has three entrances numbered even numbers, successive immediately behind. The sum of the two numbers on the outside entrances is 68. Calculate the middle of these three numbers. - Value 4

If 5/18=425 what is the value 13/18? - Diamond diagonals

Calculate the diamonds' diagonals lengths if the diamond area is 156 cm square and the side length is 13 cm. - Evaluation of expressions

If a^{2}-3a+1=0, find (i)a^{2}+1/a^{2}(ii) a^{3}+1/a^{3}