A taxi charges ₹50 plus ₹12 per km. A passenger has ₹290. What is the greatest whole number of km she can travel?

Explanation

1. 01

   The fare must not exceed ₹290: $50 + 12x \le 290$, so $12x \le 240$.

2. 02

   $x \le 20$: at most 20 km.