Higher November 2018 Paper 2 Q14

(a) Albert sells bird food in 28·8 kg sacks.
The bird food is a mix of millet, peanuts and sunflower seeds.
It contains, by mass, the millet, peanuts and sunflower seeds in the ratio 4 : 5 : 7.

To make the bird food mix, Albert pays

• 95p per kg for millet,
• £1.04 per kg for peanuts, and
• 75p per kg for sunflower seeds.

On Friday, Albert sold twelve 28·8 kg sacks of bird food for £29.99 each.

How much profit did Albert make from selling the bird food on Friday? [5]

(b) Nicole and Arthur share a house with a garden.

The probability that Nicole feeds the birds on a Saturday is 0·65.
When Nicole does not feed the birds, the probability that Arthur feeds the birds is 0·72.

Arthur says to Nicole,

‘The probability that the birds are not fed in our garden on a Saturday is less than 10%.’

Show that Arthur is correct.
You must show all your working. [4]