B's income is £ , and his spend is of A's spend. So he spends £ £ . Therefore he saves £ £ .
I'll leave you to work out C's spend and saving in the same way.
When you've done that, write the savings as a ratio , and simplify the result. I reckon the final answer is .
2) . So the weight of the smallest piece is of the weight of the original single diamond. So its value is the square of this fraction multiplied by the original value, which is:$ $Work out the value of the other two pieces in the same way. Add these values together, and subtract from $ to find the total loss in value. I reckon the answer is $ .