- 9th grade (14y) - math problems

Number of problems found: 3183

  • Serial resistors
    series-of-resistances-1 In the circuit shown ( two resistiors R1 and R2 serial connected), the total resistance from A to B is 16 ohms. Find the resistance R2 and the current through the R1 = 12-Ohm resistor, if voltage between A and B is 10 V.
  • Given 2
    eq2_fx Given g(x)=x2+x+1 where x=t2. What is g(t²)?
  • Circle inscribed
    vpisana There is a triangle ABC and a circle inscribed in this triangle with radius 15. The point T is the point of contact of the inscribed circle with the side BC. What is the area of the triangle ABC if | BT | = 25 a | TC | = 26?
  • Bridge diagonally across the river
    bridge The width of the river is 89 m. For terrain reasons, the bridge deviates from a common perpendicular to both banks by an angle of 12° 30 '. Calculate how many meters the bridge is longer than the river.
  • The isosceles
    rr_lichobeznik The isosceles trapezoid ABCD has bases of 18 cm and 12 cm. The angle at apex A is 60°. What is the circumference and content of the trapezoid?
  • A vendor
    sale A vendor bought an article for $900 and solid it for $1260. What is the profit percentage?
  • Ice to boiling water
    ice_cubes Calculate the heat needed to convert 5kg of ice with a temperature of -5°C to water with a temperature of 100°C. c (water) = 4200 J. Kg-1. kg-1, c (ice) = 2100 J. Kg-1. kg-1. the mass group heat of solidification of water is l = 334kJ/kg. Calculate the he
  • Perfect cube
    cube-root Which of the following number is not a perfect cube? a. 64 b. 729 c. 800 d. 1331
  • The library
    books Anna stored a total of 126 books in three compartments of the library. There are 6 books more in the first compartment than in the second one. The number of books in the second compartment is the arithmetic average of the number of books in the first and
  • Two numbers
    eq1 One number is by 79 larger than the other. If we divide the larger number by the smaller one, we get the ratio 5 and the remainder 11. Determine both numbers.
  • Strawberries
    jahoda Three people pick strawberries from 48 rows in 8 hours. How many hours do five people need to pick strawberries from 20 rows?
  • Colorado
    Colorado The state Colorado has the shape of a rectangle. The map is sold on 2 posters. The first has dimensions of 70 cm and 50 cm in a scale of 1: 1,000,000. The second poster has dimensions of 175 cm and 125 cm. What is the scale of the second poster?
  • Three animals
    cow Ramrao bought a cow, a buffalo and an ox for a total of rs 85,000. if the ratio of price of cow, buffalo and ox is 4: 8: 5, then what is the price of ox?
  • Wonderland
    bus27 The cost of admission to wonderland is 51.75. each bus we take costs 267.50 and holds 48 passengers. If 3 classes of 27 and their teacher wanted to go. How much would they need to fundraise?
  • The bricklayer
    murar The bricklayer built a six-meter base of the fence in 3 hours. How long does it take to build a 14 m long base?
  • Dimensions 3
    rectangle A perimeter of a rectangular field is 96 meters. The length is four meters less than three times the width. Find the length and width (its dimensions).
  • The charity
    penize Amy will donate up to $460 to charity. The money will be divided between two charities: the city youth fund and the educational growth foundation. Amy would like the amount donated to the educational growth foundation to be at least four times the amount
  • Salt solution
    Salt-Sodium-Chloride-NaCl Calculate the weight of a 50% salt solution that we prepare from 120 g of salt.
  • The flag
    germanyflag The flag should consist of 3 different colored stripes. Available colors: white, red, blue, green and yellow. Specify: A) number of all flags B) number of flags with a blue stripe C) number of flags with a blue stripe in the middle D) the number of flags
  • The vaccination
    covid19 The vaccination coverage of the population is 80%. Unvaccinated make up 60% of all infected. What percentage are unvaccinated more likely to be infected?

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