Can you guess what the numbers 20 and 150 in the equation $y = 20x + 150$ represent (Refer to Example 11 on NCERT page no. 26)?                                                                                                                                                                       [Page No. 27]

In this problem $x$ is the data used (in GB) and $y$ is the monthly bill in rupees.

• 20 is the cost per GB of data the bill goes up by ₹20 for every extra GB used.
(In $y = ax + b$, this is $a$, the slope.)

• 150 is the fixed monthly fee the amount charged even when no data is used (when $x = 0$, $y = 150$).
(In $y = ax + b$, this is $b$, the $y$-intercept.)