Math practice for 13 year olds - page 8 of 422
Number of problems found: 8424
- Consecutive odd nums  Sum of four consecutive odd numbers is 40. Find the numbers. Sum of four consecutive odd numbers is 40. Find the numbers.
- Time and distance  A man walking at a speed of 4 km/h can reach a destination in 3 hours. If he increases his speed by 1 km/h, how much time will he save? A man walking at a speed of 4 km/h can reach a destination in 3 hours. If he increases his speed by 1 km/h, how much time will he save?
- Spheres to cone  Two solid spheres of radii 2 cm and 4 cm are melted and recast into a cone of height 8 cm. Find the radius of the cone so formed. Two solid spheres of radii 2 cm and 4 cm are melted and recast into a cone of height 8 cm. Find the radius of the cone so formed.
- A train 3  A train takes 3 hours to go from one station to another station. If its speed is decreased by 12 km/h then the journey time will increase by 45 min. What is the distance between the two stations? A train takes 3 hours to go from one station to another station. If its speed is decreased by 12 km/h then the journey time will increase by 45 min. What is the distance between the two stations?
- The remainder  Find the remainder if 17²00 is divided by 18. Find the remainder if 17²00 is divided by 18.
- A contractor 2  A contractor has to complete his contract in 92 days. 234 men were set to do the work, each of them works for 16 hours/day. After 66 days, 4/7 of the work is completed. How many additional men may be employed, so that the work may be completed in time, ea A contractor has to complete his contract in 92 days. 234 men were set to do the work, each of them works for 16 hours/day. After 66 days, 4/7 of the work is completed. How many additional men may be employed, so that the work may be completed in time, ea
- The square - midpoints  The area of a square ABCD is 36 cm². Find the area of the square obtained by joining the midpoints of the sides of the square ABCD. The area of a square ABCD is 36 cm². Find the area of the square obtained by joining the midpoints of the sides of the square ABCD.
- The average 16  The average of 50 numbers is 38. If the two numbers 45 and 55 are not considered, what will be the average of remaining numbers? The average of 50 numbers is 38. If the two numbers 45 and 55 are not considered, what will be the average of remaining numbers?
- Gain or loss  A man purchases a certain number of apples at 3/eur and same number of apples at 4/euros. He mixed them together and sells them at 3/euros. What is the gain or loss percent? Write answer as number, loss as negative, gain as positive percent. A man purchases a certain number of apples at 3/eur and same number of apples at 4/euros. He mixed them together and sells them at 3/euros. What is the gain or loss percent? Write answer as number, loss as negative, gain as positive percent.
- Number of sides  Find the number of sides of a regular polygon whose each exterior angle has a measure of 45°. Find the number of sides of a regular polygon whose each exterior angle has a measure of 45°.
- Freezing  A certain freezing process requires that room temperature be lowered from 40°C at the rate of 5°C per hour.What will be the room temperature 12 hours after the process begins? A certain freezing process requires that room temperature be lowered from 40°C at the rate of 5°C per hour.What will be the room temperature 12 hours after the process begins?
- Time interval  Find the time interval between 7:40 AM and 1 : 20 PM. Find the time interval between 7:40 AM and 1 : 20 PM.
- Angle of elevation  The angle of elevation of the top of an unfinished pillar at a point 150 m from its base is 30°. If the angle of elevation at the same point is to be 45°, then the pillar has to be raised to a height of how many meters? The angle of elevation of the top of an unfinished pillar at a point 150 m from its base is 30°. If the angle of elevation at the same point is to be 45°, then the pillar has to be raised to a height of how many meters?
- The distance 4  The distance between two towns is 120 km there are approximately 8 km in each 5 mi. Which measurement is closest to the number of miles between each two towns? The distance between two towns is 120 km there are approximately 8 km in each 5 mi. Which measurement is closest to the number of miles between each two towns?
- Lemon tarts  A baker made some lemon tarts. He sold 40% of the tarts in the morning, 2/5 of the remaining tarts in the afternoon and had 54 tarts left. How many tarts did he bake altogether? A baker made some lemon tarts. He sold 40% of the tarts in the morning, 2/5 of the remaining tarts in the afternoon and had 54 tarts left. How many tarts did he bake altogether?
- A student 8  A student was asked to write 25 * 9² . By mistake he write 2592. Find the difference. A student was asked to write 25 * 9² . By mistake he write 2592. Find the difference.
- Two trains 12  Two trains 128m and 132m long are running towards each other on parallel lines at 42km/h and 30km/h respectively. In what time will they clear of each other from the moment they meet? Two trains 128m and 132m long are running towards each other on parallel lines at 42km/h and 30km/h respectively. In what time will they clear of each other from the moment they meet?
- One combine  One combine harvester can harvest a field of corn in 4.5 hours. Another harvester can harvest the same field in 3 hrs. If the farmer uses the two harvesters at the same time. How long will it take to harvest the entire field? One combine harvester can harvest a field of corn in 4.5 hours. Another harvester can harvest the same field in 3 hrs. If the farmer uses the two harvesters at the same time. How long will it take to harvest the entire field?
- A tank 2  A tank can be filled by a pipe A in 3 hours and by pipe B in 5 hours. When the tank is full, it can be drained by pipe C in 4 hours. If the tank is initially empty and all three pipes are open, how many hours will it take to fill up the tank? A tank can be filled by a pipe A in 3 hours and by pipe B in 5 hours. When the tank is full, it can be drained by pipe C in 4 hours. If the tank is initially empty and all three pipes are open, how many hours will it take to fill up the tank?
- Length measurement  Choose the measurement closest to 60 cm: ... Choose the measurement closest to 60 cm: ...
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