Daily Practice - Higher Plus

A bag holds 5 counters, r of them red. Two are taken without replacement and P(both red) = 1/10. Work out r.

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

Rationalise the denominator of 21/√7, giving your answer in its simplest form.Rationalise the denominator of 21/sqrt(7), giving your answer in its simplest form.

Solve 4x² - 9 = 0.Solve 4x^2 - 9 = 0.

y is inversely proportional to x². When x = 2, y = 64. Work out y when x = 4.y is inversely proportional to x^2. When x = 2, y = 64. Work out y when x = 4.