Higher Plus

A bag holds 4 red, 6 blue and 6 green counters. Two are taken without replacement. Given neither is green, what is the probability both are red?

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

A block has mass 470 g (to the nearest 10 g) and volume 20 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 470 g (to the nearest 10 g) and volume 20 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Solve x² + 13x + 40 > 0.Solve x^2 + 13x + 40 > 0.

y is inversely proportional to x². When x = 2, y = 75. Work out y when x = 5.y is inversely proportional to x^2. When x = 2, y = 75. Work out y when x = 5.