Postage cost and direct proportionality

Postage cost and direct proportionality

Secondary 2
TGM Original Questions

A postage cost \(P\) dollars is directly proportional to package weight \(w\) grams. A \(600\) g item costs \(\$1.50\).

  1. Express \(P\) in terms of \(w\).
  2. Find the weight in kilograms when \(P=\$3.25\).
  3. The revised price table is shown. Is the revised cost directly proportional to weight? Explain.
Weight \(w\) gPostage cost \(P\)
\(250\)\(1.25\)
\(400\)\(2.00\)
\(900\)\(4.40\)

Solution:

Solution locked

Sign in to view the step-by-step solution

Similar questions are unavailable for this question.
Answer:(a) \(P=\frac{w}{400}\); (b) \(1.3\) kg; (c) no: \(1.25/250=2.00/400=0.005\), but \(4.40/900\ne0.005\).

Need help? Join our JC Math tuition classes.

Learn more