Higher Plus

On a histogram, a 5-wide bar and a 10-wide bar have the same frequency density of 3. How many more values are in the wider class?

A block has mass 650 g (to the nearest 10 g) and volume 7 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 650 g (to the nearest 10 g) and volume 7 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Solve x² + 2x - 8 < 0.Solve x^2 + 2x - 8 < 0.

A tram runs at 5 m/s for 20 s, then slows steadily to rest over 4 s. Work out its average speed for the whole journey, to 2 decimal places.

The point (8, 15) lies on the circle x² + y² = 289. Work out the gradient of the tangent to the circle at that point.The point (8, 15) lies on the circle x^2 + y^2 = 289. Work out the gradient of the tangent to the circle at that point.