A graph is drawn below - OCR - GCSE Maths - Question 21 - 2017 - Paper 1

Since q is directly proportional to r, we can express this relationship as:

$q = k imes r$

Where k is the constant of proportionality. To find k, we use the information given:

When r = 20, q = 68:

$68 = k imes 20$

Solving for k gives:

$k = \frac{68}{20} = 3.4$

Now, we can find q when r is 25:

$q = 3.4 \times 25 = 85$

Thus, q when r is 25 is 85.