Factorise the following completely.
$$x^2-3x-28$$

The probability that a train is late is 0.15 .

Write down the probability that the train is not late.

Find the median ... kg

Find the interquartile range .... kg

Simplify, giving your answer as a single power of 7.

$$7^5\ x\ 7^6$$

Simplify, giving your answer as a single power of 7.

$$7^{15}:7^5$$

Simplify, giving your answer as a single power of 7.

42 + 7

Simplify

$$\left(5x^2.2xy^4\right)^3\$$

$$P\ =\ 2^5x\ 3^3\ x\ 7\ \ \ \ \ \ \ \ \ \ Q=540$$

Find the highest common factor (HCF) of P and Q

$$P=2^5\ x\ 3^3\ x\ 7\ \ \ \ \ \ \ \ \ \ Q=540$$

Find the lowest common multiple (LCM) of P and Q

A 2.5-litre tin of paint costs $13.50 .

In a sale, the cost is reduced by 14%.

Work out the sale price of this tin of paint.

$.............

A 2.5-litre tin of paint costs $13.50 .

In a sale, the cost is reduced by 14%.

Work out the cost of buying 42.5 litres of paint at this sale price.
$ ............................................

Henri buys some paint in the ratio

red paint : white paint : green paint = 2 : 8 : 5.

Find the percentage of this paint that is white.
...............%

Henri buys some paint in the ratio

red paint : white paint : green paint = 2 : 8 : 5.

Henri buys a total of 22.5 litres of paint.

Find the number of litres of green paint he buys.

................ litres