Question

Murphy loves pistachio nuts. Every Saturday morning, she walks to the market and buy some. Last week, she bought two pounds and paid $7.96, and this week she bought only one half pound and paid $1.99, what's the constant rate of proportionality?

Answer 1

3.98

Explanation:

From the above question,

Cost is directly proportional to the Number of pounds

Hence:

C ∝ N

= C = kN

Where k = Proportionality constant

We are told:

Last week, she bought two pounds and paid $7.96,

Hence:

7.96 = 2k

k = 7.96/2

k = 3.98

This week she bought only one half pound and paid $1.99,

1.99 = k × 1/2

k = 1.99/ 1/2

k = 3.98

Hence, the constant rate of proportionality is 3.98