Higher Plus

A bag holds 5 red and 4 blue counters. Two are taken without replacement. Given the first was red, what is the probability the second is blue?

On a histogram the bar for 0 < x ≤ 10 has a frequency density of 0.4. How many values are in that class?On a histogram the bar for 0 < x <= 10 has a frequency density of 0.4. How many values are in that class?

A block has mass 550 g (to the nearest 10 g) and volume 24 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 550 g (to the nearest 10 g) and volume 24 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Solve x² + y² = 841 and y = x + 1 simultaneously.Solve x^2 + y^2 = 841 and y = x + 1 simultaneously.

y is directly proportional to x³. When x = 2, y = 32. Work out y when x = 3.y is directly proportional to x^3. When x = 2, y = 32. Work out y when x = 3.