Daily Practice - Higher Plus

A bag holds 4 red and 5 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 1, 0.5, 3, 2. Which class contains the median?

A block has mass 840 g (to the nearest 10 g) and volume 22 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 840 g (to the nearest 10 g) and volume 22 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Solve x² + y² = 100 and y = x + 2 simultaneously.Solve x^2 + y^2 = 100 and y = x + 2 simultaneously.

y is directly proportional to √x. When x = 25, y = 40. Work out y when x = 36.y is directly proportional to sqrt(x). When x = 25, y = 40. Work out y when x = 36.