Higher Plus

On a histogram, a 4-wide bar and a 12-wide bar have the same frequency density of 2.5. How many more values are in the wider class?

A block has mass 400 g (to the nearest 10 g) and volume 23 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 400 g (to the nearest 10 g) and volume 23 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Solve 15x² + 14x - 8 = 0.Solve 15x^2 + 14x - 8 = 0.

A cyclist speeds up steadily from 10 m/s to 28 m/s over 8 seconds. Use the area under the velocity-time graph to find the distance travelled.

In a circle theorem proof, a step uses the fact that a triangle is drawn from the ends of a diameter to a point on the circle. State the reason being quoted.