Higher Plus

A histogram has two bars: one 10 units wide with frequency density 1.2, one 10 units wide with density 3. How many values in total?

A block has mass 710 g (to the nearest 10 g) and volume 12 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 710 g (to the nearest 10 g) and volume 12 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Write 5/(x + 5) + 2/(x - 5) as a single fraction.

y is directly proportional to x². When x = 4, y = 144. Work out the positive value of x when y = 81.y is directly proportional to x^2. When x = 4, y = 144. Work out the positive value of x when y = 81.

The point (9, 12) lies on the circle x² + y² = 225. Work out the gradient of the tangent to the circle at that point.The point (9, 12) lies on the circle x^2 + y^2 = 225. Work out the gradient of the tangent to the circle at that point.