Math practice for 13 year olds - page 13 of 359
Number of problems found: 7169
- The reflection law
AB is a mirror, PQ is the incident ray, and QR is the reflected ray. If angle PQR = 112°, find angle PQA. - Complement and supplement
Find the measure of an angle if 7 times its complement is 10° less than 3 times its supplement. - An electrician 7
An electrician has to repair an electric fault on a pole 4 meters in height. He needs to reach a point 1 m below the top. What should be the length of the ladder that he could use, when inclined at an angle 60° to the horizontal? - Two discounts 2
A shirt printed with a price of EUR 150 is sold for EUR 105 after two successive discounts. If the second discount is 12.5%, then find the first discount.
- Cylinders and cube
How many cylinders of radius 20 cms and height 0.7 metres can be formed by melting a cube of 2.2 metres sides? - An equilateral triangle 2
If the sides of an equilateral triangle are increased by 2 meters, the area is increased by 7√3 square meters. Find the length of the side. - The price 8
The price of a commodity has decreased by 10%. What is the percentage by which it should then be increased to get the original price? - Petrol, fuel
In a car meter shows that it has kept oil 1/5 of its fuel capacity. When 22 liters of petrol is filled the meter went on 3/4 of its capacity. Find the capacity of the car. - Three numbers
In three numbers, the first number is double the second number, and the second number is double the third. The average of the numbers is 21. Find the least number.
- A pen 2
A pen cost 1 USD plus half its price. How much does it actually cost? - Family members
Three years ago, the average age of a family of five members was 27. The present average age is also 27 after a child is included in the family. Find the age of the child. - Profit sharing
Three people, A, B, and C, started a business by investing Rs. 250000, Rs. 300000, and Rs.350000, respectively. Find the share of B out of an annual profit of Rs.187200. - One half of percent How is 1/2% expressed as a decimal fraction?
- Men at work 8 men can finish a piece of work in 40 days. If 2 more men joined with them, then how many days it will take to complete the work?
- Parallel tracks
Two trains cross each other in 14 seconds when running in opposite directions along parallel tracks. The faster train is 160 m long and crosses a lamp post in 12 seconds. If the speed of the other train is 6 km/hr less than the faster one, its length, in - Four points
There are 4 nonlinear points. How many triangles can form by joining them? - Diagonals
What is the number of diagonals of a decagon? - Unknown en
I think of a number. If I subtract 9 from it and multiply this difference by 4, the result is 128. Form an equation and solve it to find the number. - A tree 2
A tree is broken at a height of 6 m from the ground and its top touches the ground at a distance of 8 m from the base of the tree. Find the original height of the tree.
If the sides of a triangle are 26 cm, 24 cm, and 10 cm, what is its area?Do you have unsolved problem that you need help? Ask a question, and we will try to solve it. Solving math problems.
