Daily Practice - Higher Plus

A bag holds 11 counters, r of them red. Two are taken without replacement and P(both red) = 6/55. Work out r.

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

A block has mass 320 g (to the nearest 10 g) and volume 3 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 320 g (to the nearest 10 g) and volume 3 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

f(x) = 5x - 3. Work out the inverse function f^-1(x).f(x) = 5x - 3. Work out the inverse function f^-1(x).

y is inversely proportional to x². When x = 5, y = 72. Work out y when x = 6.y is inversely proportional to x^2. When x = 5, y = 72. Work out y when x = 6.