39537

1. It's impossible for Sinead because the minimum amount of pounds she needs is at least £55.

2. It's impossible because if you add up 1,2,3,4,5,6,7,8,9,10 = 55 and you can't halve 55.

3. If n = 5 then you can because 1,2,3,4,5 = 15 and you can not halve it but if n = 8 then 1,2,3,4,5,6,7,8 = 36 and you can half 36 into 18 so one tower can be 4,6 and 8 and the other tower can be 1,2,3,5and 7 as both towers add up to the same number so it depends what n is = to.

4. It is impossible because if you try any 4 numbers they won't add up to a multiple of 4.