Two step problems

I have read 12 pages of

my book there are

40 pages altogether. How many to the middle?

There are 8 pages to the middle.

I buy 3 apples costing 99p each and a carton of milk costing £1.99. How much change will I get from £10 note.

I have got 6 sweet and my friend has two. How many Sweets do we have together? and if we gave 4 sweets to are friend ,how many sweet would we have left?

Sarah needs18 peppers for a salad which will serve 6 people. How many peppers for 4 people