# Father and daughter

When I was 11 my father was 35 year old. Now, father has three times older then me. How old is she?

Result

y =  12

#### Solution:

35+x = 3*y
y = 11+x

x-3y = -35
x-y = -11

x = 1
y = 12

Calculated by our linear equations calculator.

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

Be the first to comment!

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

Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?

## Next similar examples:

1. 600 pencils
600 pencils we want to be divided into three groups. The biggest groups have ten pens more than the smallest. How many ways can this be done?
2. Three numbers
We have three different non-zero digits. We will create all 3 digits numbers from them to use all 3 figures in each number. We add all the created numbers, and we get the sum of 1554. What were the numbers?
3. Spherical cap
Place a part of the sphere on a 4.6 cm cylinder so that the surface of this section is 20 cm2. Determine the radius r of the sphere from which the spherical cap was cut.
4. Triangle 42
Triangle BCA. Angles A=119° B=(3y+14) C=4y. What is measure of triangle BCA=?
5. 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?
6. Rectangle
There is a rectangle with a length of 12 cm and a diagonal 8 cm longer than the width. Calculate the area of rectangle.
7. Banknotes
Eva deposit 7800 USD in 50 banknotes in the bank. They had value 100 USD and 200 USD. How many were they?
8. Average height
The average height of all pupils is 162 cm. The class teacher's height is 178 cm. The average height of all (teacher and all pupils) is 163 cm. Calculate the number of pupils in the class.
9. Balloon and bridge
From the balloon, which is 92 m above the bridge, one end of the bridge is seen at a depth angle of 37° and the second end at depth angle 30° 30 '. Calculate the length of the bridge.
10. Find the sum
Find the sum of all natural numbers from 1 and 100, which are divisible by 2 or 5
11. The size
The size of a Trapezium are 3/4×cm, ×cm 2(×+1)cm and 3(×+2)cm long respectively if it's perimeter is 60cm, calculate the length of each side.
12. The painter
In order for the painter to get the desired color, he must mix green and yellow in a ratio of 4: 7. If it has 28 l of green color, how many liters of yellow color should he add? How many liters of mixed color does he get?
13. Prism diagonal
The body diagonal of a regular square prism has an angle of 60 degrees with the base, the edge length is 10 cm. What is the volume of the prism?
14. Triangular pyramid
What is the volume of a regular triangular pyramid with a side 3 cm long?
15. KLM triangle
Find the length of the sides of the triangle KLM if m = 5cm height to m = 4.5 cm and size MKL angle is 70 degrees.
16. Average temperature
The average temperature from Monday to Sunday was 40.5 and the average temperature from Monday to Saturday was 42.8. What was the temperature on Sunday?
17. Wave parameters
Calculate the speed of a wave if the frequency is 336 Hz and the wavelength is 10 m.