Higher Plus

On a histogram, a 4-wide bar and a 12-wide bar have the same frequency density of 2. How many more values are in the wider class?

Simplify 12 + 147, giving your answer in the form a b.Simplify sqrt(12) + sqrt(147), giving your answer in the form a sqrt(b).

In an algebraic proof, how would you write an odd number in terms of an integer n?

A tram runs at 19 m/s for 20 s, then slows steadily to rest over 6 s. Work out its average speed for the whole journey, to 2 decimal places.

The point (12, 16) lies on the circle x² + y² = 400. Work out the gradient of the tangent to the circle at that point.The point (12, 16) lies on the circle x^2 + y^2 = 400. Work out the gradient of the tangent to the circle at that point.