A's profit = \(\frac{x-z}{z}\), and B's profit = \(\frac{y-z}{z}\)

% change of A over B = \(\frac{A's.profit-B's.profit}{b"s.profit}*100...........\frac{\frac{x-z}{z}-\frac{y-z}{z}}{\frac{y-z}{z}}*100=\frac{\frac{x-y}{z}}{\frac{y-z}{z}}*100=\frac{x-y}{y-z}*100\)...

Hence, we require values of x, y and z OR values of x-y and y-z

We have some fractions for A’s and B’s profit. When we substitute it in the formula
\(\frac{\frac{(x-z)}{z}-\frac{(y-z)}{z}}{(\frac{y-z}{z})}=\frac{\frac{(x-z-(y-z))}{z}}{\frac{((y-z)}{z)}}=\frac{(x-z-y+z)}{y-z}=\frac{(x-y)}{(y-z)}\)
Now we know x-y and y-z can be found from the two statements.
Subtract statement I from ii
\((x-z)-(x-y)=40-20=20....y-z=20\)

Statement I and II give us these values when combined
Answer = \(\frac{20}{20}*100=100%\)
y-z can be found by subtracting Statement I from statement II

C
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Not sure if I agree with the answer;

I think it should be a ratio for percent of A/ B. Not percent change formula as we are not dealing with one item and seeing how they change over time.

Also, I set up the equations like this: PROFIT (A)= REVENUE- COST = X-Z / PROFIT (B) = Y-Z

SO (X-Z)/ (Y-Z). This is the equation to use for both statements.

1) SInce Z is the same and based on profit formula can we conclude that x is 20 % more than y. Sufficeint.

2) 40/ (y-z). Not Suff.

Thanks