# Equation - 7th grade (12y) - math problems

#### Number of problems found: 521

• Car and cyclist
Cyclist started from town at speed 18 km/h. After 1 hour 30 min started the car from town and caught up with the cyclist in 50 minutes. How fast was a car?
• Library
New books were purchased for the library. Five-eighths were professional books, one-fifth were encyclopedias, and 231 books were dictionaries. How many professional books were there?
• Three pumps
The water tank is emptied with the first pump in 6 hours, with the second pump in 2 hours. In order to be emptied in 1 hour, all three pumps had to be started at once. How long will take tank be emptied by only the third pump?
• Work together
Two bricklayers plastering a wall. The first would plaster it in 8 hours, the second in 12 hours. How many hours will they be done with the work if they work together?
• Boats
Three-quarters of boats are white, 1/7 are blue and 9 are red. How many boats do we have?
• Tickets 3
A total of 645 tickets were sold for the school play. They were either adult tickets or student tickets. There were 55 fewer student tickets sold than adult tickets. How many adult tickets were sold?
• Troops
There are two leaders in the tourist group, with an average age of 30 years and several children with an average age of 10 years. The total age of the group is 12 years. How many children are in the group?
• 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?
• One third
If 3/5 is 360, how much is 1/3?
• Bicycle gears
The toothed wheel on the bicycle pedal has 40 teeth, the wheel on the rear wheel has only 16 teeth. How many times does the rear wheel turn if the pedals rotate 50 times?
• Equation 15
Solve equation with variables on both sides:
• Unknown numbers
The sum of two consecutive natural numbers and their triple is 92. Find these numbers.
• Unknown number 6
Determine the unknown number, which is by 1.5 greater than its fourth.
• Crown coins
Jana saves two-crown and five-crown coins. She has ten coins in the cashier. How many two crowns and how many five crowns shw have if she saved 29 crowns?
• A map
A map with a scale of 1: 5,000 shows a rectangular field with an area of 18 ha. The length of the field is three times its width. The area of the field on the map is 72 cm square. What is the actual length and width of the field?
• Equation 11
Solve equation: ?
• Clothes
Danka and Janka collect clothes. Danka had 9 more than Janka, so she gave her 7. Which now has more cloth and how many?
• Sale off 2
A pair of of blues jeans went on sale. After a 30% reduction the pants cost \$35. How much did the jeans cost before the price reduction?
• Unknown number 24
f we add 20, we get 50% of its triple. What is this unknown number?
• Rectangles
Vladimir likes to draw rectangles. Yesterday he created all rectangles that had sides in centimeters and a circumference of 18 cm. How many rectangles of different dimensions have been drawn?

Do you have an interesting mathematical word problem that you can't solve it? Submit a math problem, and we can try to solve it.

We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...

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