Final answer:
The change received after buying petrol for $17.34 and paying with a $50 note is $32.66.
Step-by-step explanation:
To calculate the change received after paying for petrol with a $50 note, we need to subtract the amount spent on petrol from the amount paid. In this case, you have filled up your car with petrol for $17.34. Subtract that from the $50 note you are paying with:
$50.00 - $17.34 = $32.66
Therefore, the change you will get back after paying with a $50 note is $32.66.