63 is only 63% of the number 100.
Answer:

Step-by-step explanation:
Exponential function
is
increasing if 
decreasing if 

Saw A = 150 planks/30 seconds = 5 planks per second
Saw B = 130 planks/ 13 seconds = 10 planks per seconds
5 + 10 = 15 planks per second total
225 planks / 15 planks per second = 15 seconds
Answer: 15 seconds
I don’t understand you buddy :/