I've read on here that being very familiar with all the different ways of presenting a maths problem as you can, will stand one in good stead, particularly for CEM which is still a bit of an unknown quantity (think there's a pun in there, somewhere!).

I've been looking at the City of London School for Girls paper from 2010. The problem solving type questions (examples below) are really frightening me

. I had thought I'd be able to help DS, but looking at this, I have NO IDEA how to go about these. Are there standard ways/ formulae for approaching these questions?

ABCD is a four digit number

* Its first digit is 1/4 of its last digit

* The second digit is 1 less than its first digit

* When you multiply ABCD by 4, its digits appear in reverse order

* None of the digits are the same.

What is the number?

Some fairy cakes are delivered for Janey's party.

Janey can use big plates or small plates to put the cakes on.

If she uses big plates she can put 7 cakes on each plate with 5 left over.

If she uses small plates she can put 5 cakes on each plate with 3 left over.

What is the smallest number of cakes that were delivered for Janey's party?

The smallest number of cakes are delivered for Janey's party.

(a) If she only used big plates for the cakes, how many big plates would she need?

(b) If she only used small plates for the cakes, how many small plates would she need?