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.

On a histogram the bar for 30 < x ≤ 50 has a frequency density of 3.5. How many values are in that class?On a histogram the bar for 30 < x <= 50 has a frequency density of 3.5. How many values are in that class?

A car covers 720 m (to the nearest 10 m) in 4 s (to the nearest second). Work out the lower bound of its speed, to 2 decimal places.

Solve x² + y² = 25 and y = x + 1 simultaneously.Solve x^2 + y^2 = 25 and y = x + 1 simultaneously.

y is directly proportional to x³. When x = 2, y = 48. Work out y when x = 4.y is directly proportional to x^3. When x = 2, y = 48. Work out y when x = 4.