Equation - examples
- 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?
- 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 spent 5/11 of her money on a back pack. She has $42 dollars left. How much was her back pack?
- Diamond diagonals
Calculate the diamonds' diagonals lengths if the diamond area is 156 cm square and the side length is 13 cm.
Each box has the same number of soaps. A quarter of all boxes contain only white soaps, and in each of the remaining 120 boxes there are always half the white soaps and half the green. White soaps total 1200. (a) the number of all soap boxes; (b) the sma
- Train speed
Two guns were fired from the same place at an interval of 10 minutes and 30 seconds, but a person in a train approaching the place hears second shot 10 minutes after the first. The speed of the train (in km/hr), supposing that sound travels at 340 m/s is:
- Average age
The company of five people has an average age of 46 years. The average age of the first four is 43 years. How many years has the fifth member of this company?
- A residential
A residential colony has a population of 5400 and 60 litres of water is required per person per day. For the effective utilization of rain water, they constructed a water reservoir measuring 48m × 27m × 25m to collect the rain water. For how many days, the
- Equilateral triangle
Calculate the area of an equilateral triangle with circumference 72cm.
Calculate the length of a side of the equilateral triangle with an area of 50cm2.
Twenty rabbits are put in 4 cells so that there are different number of rabbits in each cell contains at least 3 rabbits. What is the largest possible number of rabbits in one cell
- Dropped sheets
Three consecutive sheets dropped from the book. The sum of the numbers on the pages of the dropped sheets is 273. What number has the last page of the dropped sheets?
- 12 apples
12 apples and 2 loaves of bread cost 5.76 and 6 apples and 3 loaves of bread cost 7.68. How much is a loaf of bread?
The airplane from Prague to Bratislava was flying at a speed of 60 km/h less and back by 70 km/h greater than the original speed. What was the original speed if the plane returned to Prague according to the timetable?
- Exponential warm
Suppose that a body with temperature T1 is placed in surroundings with temperature T0 different from that of T1. The body will either cool or warm to temperature T(t) after time t, in minutes, where T(t)=T0 + (T1-T0)e^(-kt) . If jello salad with 30 degre
- What is
What is the value of the smaller of a pair of numbers for which their sum is 78 and their division quotients are 0.3?
- Map scale
The rectangular plot has in a scale of 1: 10000 area 3 cm2 on the map. What content does this plot have on a 1:5000 scale map?
- 13 tickets
A short and long sightseeing tour is possible at the castle. Ticket for a short sightseeing circuit costs CZK 60, for a long touring circuit costs CZK 100. So far, 13 tickets have been sold for 1140 CZK. How much did you pay for tickets for a short tour?
- Three points 2
The three points A(3, 8), B(6, 2) and C(10, 2). The point D is such that the line DA is perpendicular to AB and DC is parallel to AB. Calculate the coordinates of D.
Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?