Answer:
C: 800 x 20
Step-by-step explanation:
Basically, when you round 778 you see that the 7 and 8 are above 5, which means you round upwards. Therefore it would be best to round up to 800.
Then the 3 in 23 is below 5, meaning you round downwards. 20 Is the closest and best option.
So, C: 800 x 20 is best to do!
