Aluminium is a non magnetic metal. However, it can become magnetised under special conditions. Explain how. (4 marks)

Exposing it to a very strong magnetic field

Explanation:

Aluminium is a non magnetic metal thus it is not magnetic under normal conditions. This is because it interacts with other magnets. The only condition that magnetism can be induced in aluminium is exposing it to a very strong magnetic field.

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

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