Examples of equations for 7th grade (12y)

Number of problems found: 529

• Large family
The average age of all family members (children, mother, father, grandmother, grandfather) is 29 years. The average age of parents is 40 years, grandparents 66 years and all children are 5 years. How many children are there in this family?
• Boys and girls
There are 28 girls in the hall. 5/7 of all children are boys. How many children and how many boys are there?
• Flour
Kim needs 3/4 cup of flour to make 12 cookies. How much flour would she need to make 60 cookies?
• Rhombus
If we increase the rhombus side by 2.4 cm; its perimeter is 20 cm. How long was the side of the rhombus?
• Unknown number 5
Daniel think an integer. When he change this number at a ratio of 2:5 he got number 2.8. Determine what number think Daniel.
• Two ages
Gabrielle is 9 years younger than Mikhail. The sum of their ages is 87. What is Mikhail's age?
• The quotient
The quotient of g and 55 is the same as 279. What is g?
• Friends
James and Jaroslav are friends. Together they had 48 toy cars. But if John took 8 cars from Jaroslav, Jaroslav will be have 1.5 times more toy cars than James. How many toy cars had Jaroslav and James?
• Class 9.C
Professor collects money in the 9. C for a school trip. 2/3 of the collected amount was from girls and 1/4 from boys. The rest of 410 CZK went from the class fund. How much will the school trip cost in total?
• Fraction + eq
Solve following simple equation with fractions: -5/6(8+5b) = 75 + 5/3b
• Four swords
Obelix has three helmets, four swords and five shields. How many swords must make at the blacksmith forge Metallurgix to be able to walk another 90 days in unique armor?
• Guess a fraction
Tom was asked to guess a fraction. The sum of 1/2 the numerator and 1/3 of its denominator is 30. If Tom subtracts 36 from its denominator, the fraction becomes 1/3. What is the fraction that Tom was asked to guess? (Leave your answer in simplest form)
• Playing
How long have we trained on the pitch when we know that the warm-up took 10 minutes, we trained passes for one-third of the time and we played football half the time?
• Lumberjacks
Fifteen lumberjacks would take 12 days to destroy the broken trees. How many days would this work require if 5 workers added to it after 4 days?
• 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?
• Tractors
5 tractors will plow the field for 8 hours. In 2 hours, 1 tractor broke down. How long do the remaining tractors complete the plow?
• In and out
The empty tank is filled in 12 minutes and empty in 16 minutes. How long does it take to fill if we forgot to close the drain? If the tank has 1000 l.
• Two trains
From station A, the freight train traveled at a speed of 40 km/h in 9h. When he drove 15km, the fast train started from station A in the same direction at a speed of 70km/h. When will it the freight train catch up?
• Savings
Eva borrowed 1/3 of her savings to her brother, 1/2 of savings spent in the store and 7 euros left. How much did she save?
• Negative in equation
2x + 3 + 7x = – 24, what is the value of x?

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