Full volume of the tank = 65 × 50 × 32 = 104&thinsp;000 cm&sup3; = 104 L.<br><br>
&bull; Petrol used = 104 − 26 = 78 L<br>
&bull; Ratio of petrol used to petrol left = 78 : 26<br>
&bull; Simplify by dividing both terms by 26.<br>
&bull; 78 : 26 = 3 : 1<br><br>
Final Answer: 3 : 1