Valeriya

David has two boxes containing shapes. In box A there are 4 stars and 2 hearts. In box B there are 2 stars and 1 heart. David takes, at random, a shape from box A and puts it into box B.He then takes a shape from box B. What is the probability that this s...

ABCDE is a circle with centre O. The diameter, AC, is extended to the point F so that CF = 16 cm. The line BF is the tangent to the circle at B and FDE is a straight line such that FD = 18 cm and chord DE = 14 cm (D and E are points of intersection of the...

Two radioactive sources X and Y have half-lives of 3.0 hours and 2.0 hours, respectively. The product of the decay is a stable isotope of the element Z. Six hours ago a mixture contained the same number of atoms of both X and Y, and no other atoms. What f...

Car X passes car Y on a motorway. Car X is travelling at 1.5 times the speed of car Y. The mass of car X is 5/4 of the mass car Y. How do the kinetic energies of the two cars compare? (the answer is KE (X) = 1.80 * KE (Y))

A bag contains 8 blue and 2 red balls. Three balls are chosen at the same time at random from the bag. What is the probability that exactly two of the balls are the same colour?

Basket A contains 4 apples, 6 oranges, and 2 lemons. Basket B contains 5 apples, 4 oranges, and 6 lemons. You are to get two fruits from each basket. What is the probability of getting 2 oranges from basket A and then 1 apple and 1 lemon from basket B?

Two aluminium spheres P and Q, of masses 0.50 kg and 1.0 kg respectively, are released at the same time from the same height. Why do they have the same acceleration?

The trapezoid has a height of 24. E is a point where the trapezoid touches the inner circle, so that BE:EA = 9:16. Find the medsegment of the trapezoid.