Answer:
Each one can take 7 lessons.
Explanation:
Dylan and Dusty plan to take weekly surfing lessons together.
They want to spend $100 each on new surfboards = $100 × 2
 = $200
They want to spent total amount for lessons and surfboards is at most $480.
After spending on two new surfboards the money left with 
= 480 - 200
= $280
The charges for 2-hours classes for surfing lessons = $20 per person
The charges for 1 hour classes for them = $20.00
With $280 they will be able to take maximum number of lessons 
= 

= 14 lessons 
Each one can take 14/2 = 7 lessons.