It is given that \(x\) is 15% of \(y\) and \(y\) is 28% of \(z\). If \(x=1050\), then find \(z-y\).
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 18000
“\(x\) is 15% of \(y\)” means \(x=0.15y\), so \(y\) is found from \(x\), and then \(z\) from \(y\) in the same way.
\(y\) from \(x\): \(0.15y=1050\), so \(\displaystyle y=\frac{1050}{0.15}=7000\)
\(z\) from \(y\): \(0.28z=7000\), so \(\displaystyle z=\frac{7000}{0.28}=25000\)
\(z-y=25000-7000=18000\)
Tip: 25000 (Option 2) is \(z\) itself; the question asks for \(z-y\), so subtract at the end.