Daily Practice - Higher Plus

A bag holds 8 red and n blue counters. The probability of taking a red is 8/11. Work out n.

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

A block has mass 430 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 430 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.

A quadratic sequence starts 17, 35, 61, 95. Work out the second difference, and the coefficient of n².A quadratic sequence starts 17, 35, 61, 95. Work out the second difference, and the coefficient of n^2.

y is directly proportional to √x. When x = 25, y = 20. Work out y when x = 16.y is directly proportional to sqrt(x). When x = 25, y = 20. Work out y when x = 16.