He just switched sides of the variables and numbers. Instead if adding the opposite.
Answer:
B 600
Step-by-step explanation:
A clock is a circle with 12 equal sectors. A circle has 360 degrees so every time a minute hand number goes to another number it changes 30 degrees. After a full hour the time is 7 20 and it changes 360 degrees since the minute hand change over time was 12. 30x12=360.
Then it from 7 :20 and 8 00 the change 8 so is 30×8=240
360+240=600
Composition function rule (f○g)(x) = f(g(x))
<em><u /></em><u>Given the separate functions</u>:

and


Sum is addition, less than is subtraction, equals is is, division is of and multiplication is per
Side Side Side is the answer