The planes will pass each other in 1.14 hours.
Why?
To solve the problem, we must remember that since both planes are heading toward each other, the speed to the calculations will be their combined speeds.
The speed will be:

Now, calculating the time, we have:

Hence, the planes will pass each other in 1.14 hours.
Have a nice day!
Answer:
11.5 hours
Step-by-step explanation:
25 pages every 75 minutes (1 1/4)
Thats means 1 page every 3 minutes (divide 25 and 75 by 25 to get this)
230 pages would mean 690 minutes (times the 3 by 230)
690/6 = 11.5