Question

At the museum you can buy 3 postcard for 5.40 6 postcards for 10.80 or 9 postcards for 16.20 What is the constant of proportionality for buying postcard

Answer 1

x. y
3 postcards for $5.40
6 postcards for $10.80
9 postcards for $16.20
To find the constant of proportionality, take y/x, so
$5.4/3
$10.8/6
$16.2/9
They all equal $1.80/1. As a result, the constant of proportionality is $1.80 for 1 postcard. Hope it help!