Higher Plus

A bag holds 4 red and 6 blue counters. Two are taken without replacement. Given the first was red, what is the probability the second is blue?

A histogram has four 10-wide classes from 0, with frequency densities 0.5, 1, 3, 2. Which class contains the median?

Rationalise the denominator of 6/3, giving your answer in its simplest form.Rationalise the denominator of 6/sqrt(3), giving your answer in its simplest form.

Solve x² + y² = 225 and y = x - 3 simultaneously.Solve x^2 + y^2 = 225 and y = x - 3 simultaneously.

y is inversely proportional to x². When x = 2, y = 18. Work out y when x = 3.y is inversely proportional to x^2. When x = 2, y = 18. Work out y when x = 3.