Higher Plus

A bag holds 5 red, 7 blue and 6 green counters. Two are taken without replacement. Given neither is green, what is the probability both are red?

On a histogram the bar for 20 < x ≤ 25 has a frequency density of 1.5. How many values are in that class?On a histogram the bar for 20 < x <= 25 has a frequency density of 1.5. How many values are in that class?

A block has mass 540 g (to the nearest 10 g) and volume 5 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 540 g (to the nearest 10 g) and volume 5 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Write x² + 12x + 13 in the form (x + a)² + b.Write x^2 + 12x + 13 in the form (x + a)^2 + b.

y is directly proportional to x³. When x = 4, y = 128. Work out y when x = 3.y is directly proportional to x^3. When x = 4, y = 128. Work out y when x = 3.