Examples for 9th grade - page 103

1. The length The length of a rectangle is 6 meters less than twice the width. If the area of the rectangle is 216 meters, find the dimensions of the rectangle.
2. A car A car weighing 1.05 tonnes driving at the maximum allowed speed in the village (50 km/h) hit a solid concrete bulkhead. Calculate height it would have to fall on the concrete surface to make the impact intensity the same as in the first case!
3. Three workshops There are 2743 people working in three workshops. In the second workshop works 140 people more than in the first and in third works 4.2 times more than the second one. How many people work in each workshop?
4. Alice Alice spent 5/11 of her money on a back pack. She has \$42 dollars left. How much was her back pack?
5. Together If 8 men, 10 women, 16 children collects ₹1024 in 4 days, how many days will be required for 6 men, 5 women and 4 boys to collect ₹768? (₹ is Indian Rupee)
6. Collision The two bodies, whose initial distance is 240 m, move evenly against each other consistently. The first body has an initial velocity of 4 m/s and an acceleration of 3 m/s2, the second body has an initial speed of 6 m/s and an acceleration of 2 m/s2. Find
7. 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?
8. Hectoliters How deep is the pool if there are 2025 hectoliters of water and the bottom dimensions are a = 15 meters b = 7,5 meters and the water level is up to 9/10 (nine-tenths) of height.
9. Right isosceles triangle Right isosceles triangle has an altitude x drawn from the right angle to the hypotenuse dividing it into 2 equal segments. The length of one segment is 5 cm. What is the area of the triangle?
10. 600 pencils 600 pencils we want to be divided into three groups. The biggest groups have ten pens more than the smallest. How many ways can this be done?
11. Mini-survey In the mini-survey of our class about the popularity of individual subjects, it turned out that 11.1% of pupils like mathematics, 18.5% are enjoying languages, 30.4% of pupils like physical education, and the remaining 12 pupils have several popular subjec
12. Minute average In a factory, four workers are assigned to complete an order received for dispatching 1400 boxes of a particular commodity. Worker A takes 4 mins per box, Worker B takes 6 minutes per box, C takes 10 mins per box, D takes 15 mins per box. Find the average.
13. Perimeter of a rectangle If the perimeter of a rectangle is 114 meters and the length is twice the width plus 6 meters, what are the length and width?
14. Car crash On the road, with a maximum permitted speed of 60 km/h, there was a car crash. From the length of the vehicle's braking distance, which was 40 m, the police investigated whether the driver did not exceed that speed. What is the conclusion of the police, as
15. 40% volume 40% volume with 104 uph (units per labor hour) 8 people working. What is the volume?
16. Centroid - two bodies A body is composed of a 0.8 m long bar and a sphere with a radius of 0.1m attached so that its center lies on the longitudinal axis of the bar. Both bodies are of the same uniform material. The sphere is twice as heavy as the bar. Find the center of gravit
17. Potatoes For three days the store sold 1400 kg of potatoes. The first day they sold 100 kilograms of potatoes less than the second day, the third-day three-fifths of what they sold the first day. How many kgs of potatoes sold every day?
18. The tub If we drop the 5 l from the first tap and the from second 2 liters of water, the water in the tub will have a temperature of 25°C. If we drop 3 l from the first tap and from second 4 l of water, the water in the tub will have a temperature of 21°C. Determi
19. Wave parameters Calculate the speed of a wave if the frequency is 336 Hz and the wavelength is 10 m.
20. Intersections Find the intersections of the function plot with coordinate axes: f (x): y = x + 3/5

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