School A sent some students to a revision day. School B sent twice as many students as School A. School C sent 3 fewer students than School A. Each student paid £10 for the revision day. The students paid a total of £2170 Work out how many students were sent by each school to the revision day. You must show all your working.

Solve the following simultaneous equation by using an algebraic method (either substitution or elimination) 2x + 3y=-4 4x-y=11

Aroulette wheel has 38 slots in which the ball can land. two of the slots are green, 18 are red, and 18 are black. the ball is equally likely to land in any slot. the roulette wheel is going to be spun twice, and the outcomes of the two spins are independent.the probability that it lands one time on red and another time on black in any order is(a) 0.5 (b) 0.25 (c) 0.4488 (d) 0.2244

What is the inverse of the function f(x) = 2x + 1?