Daily Practice - Higher Plus

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

A block has mass 230 g (to the nearest 10 g) and volume 18 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 18 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Make x the subject of 4x + 3 = y(x + 3).

y is directly proportional to √x. When x = 4, y = 18. Work out y when x = 81.y is directly proportional to sqrt(x). When x = 4, y = 18. Work out y when x = 81.