So the time in Xiao Su is1.2x. 。

Therefore, Lao Yang copies 300/X pages per hour.

Xiao Su copies 300/ 1.2X pages per hour.

Judging from the meaning of the question:

300/X-300/ 1.2X=5

Solution: X= 10 hour, 1.2X= 12 hour.

A: It took 10 hour in Lao Yang and 12 hour in Xiao Su.