Daily Practice - Higher Plus

A bag holds 8 red and n blue counters. The probability of taking a red is 4/7. Work out n.

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

A block has mass 340 g (to the nearest 10 g) and volume 6 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 340 g (to the nearest 10 g) and volume 6 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Solve x² + y² = 625 and y = x + 17 simultaneously.Solve x^2 + y^2 = 625 and y = x + 17 simultaneously.

y is directly proportional to √x. When x = 36, y = 12. Work out y when x = 4.y is directly proportional to sqrt(x). When x = 36, y = 12. Work out y when x = 4.