Equation - examples - page 13
In the bath is 30 liters of hot water. Then added 36 liters of cold water at temperature of 19 °C decreased temperature of water to 41 °C. What was the initial temperature of the hot water?
The grandfather is three years older than an grandmother. The average age of the grandmother, the grandfather and their seven grandchildren is 28 years. The grandchildren have a total of 105 years. Calculate how old is grandfather.
- Bronze, tin and copper
Bronze is an alloy of tin and copper. An alloy of 10% tin and 90% copper is Gunmetal. If it contains 20% tin and 80% copper, it is bell metal. How many tons of molten bell metal and how many tons of copper is needed to make 100 tons of Gunmetal?
The voltage station is every day changing the master password, which consists of three letters. Code generation process does not change and is based on the following procedure: The following letters (A) to (I) correspond to different numbers from 1 to 9. I
Jan is 13 years and Peter 21 years old. For how many years will their ages in the ratio of 7:9?
- Paul and Honza
Honza went to chat on a bike without a break 4.0 hours. Paul the same way without breaks 50 minutes longer. The difference between the speeds of the two boys was the one kilometer per hour. How fast was Paul, if you know that the speed of the boys did not.
Tourist walk at 4.1 km/h. Every 5 km have 20-minute break. How many kilometers passed, when started at 4:40 and finished at 10:30?
- Isosceles triangle
The perimeter of an isosceles triangle is 112 cm. The length of the arm to the length of the base is at ratio 5:6. Find the triangle area.
- Enterprise and wages
The enterprise operates a total 162 workers and their average salary is M dollars. If the company has hire an additional 18 employees whose average wage would be the S dollars, would reduce the overall average salary in the company of 3.6%. Calculate the
- Two workers
Two workers carry will do certain work for 12 days. After 8 days of working was one removed, and then the other finished the job alone in 10 days. For how many days would do this work alone each worker?
Albert, Beny, Cyril and Dan worked on summerjob. From the total revenue Albert received 2/5, Beny 1/6 , 3/10 Cyril and Dan the rest which is 324 euros. How many euros earned every one of them?
The children were on a school trip to the mountain . One third of the journey went by the train and continue by bus. When you get off the bus, they remained a third of the distance they traveled by bus. What part of journey children went by the bus (wrote
For every 5 minutes writes Dana 10 invitations, while Anna 14 invitations. How long will write together 120 invitations?
- Sales off
If a sweater sells for $ 19 after a 5% markdown, what was its original price?
4 m long ladder touches the cube 1mx1m at the wall. How high reach on the wall?
- Mushrooms from the forest
Magda and Tereza goes to pick mushrooms. Total found 70 mushrooms. Magda found that between fungi found 5/9 bedel. Tereza discovered that she found among fungi are 2/17 champignons. How many mushrooms found Magda?
How many raffle tickets must be purchased by Peter in raffle with issued 200 tickets if he wants to be sure win at least 3 price? In the raffle draws 30 prices.
- The professor's birthday
Professor of mathematics had 57 birthdays. The director congratulated him. The professor asked the director: "And how old are you?" The director replied: "I'm exactly twice as many years than you were when I was old as to you today." How old is the direc
- Rising price
The book first become more expensive by 5 euros. New price was later increased by 8%. After the second price increase book cost 46 euros. What was the original price of the book?
- angles in quadrilateral
What size have angles in quadrilateral (4-gon) if they are in a ratio of 8: 9: 10: 13?
Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?