Daily Practice - Higher Plus

A bag holds 3 red and n blue counters. The probability of taking a red is 1/2. Work out n.

A histogram has four 20-wide classes from 0, with frequency densities 1, 0.5, 3, 2. Which class contains the median?

A block has mass 230 g (to the nearest 10 g) and volume 15 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 230 g (to the nearest 10 g) and volume 15 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Solve x² + 10x + 16 > 0.Solve x^2 + 10x + 16 > 0.

y is directly proportional to √x. When x = 49, y = 42. Work out y when x = 64.y is directly proportional to sqrt(x). When x = 49, y = 42. Work out y when x = 64.