Me on this
u need to zoom in

Not sure if you can do this but it sounds like a velocity/time/distance equation.
d=vt
v=d/t
t=d/v

70 w/m = t
15 pages - 350 w/p

She can type 70 words per minute (w/m). There are 350 words per page (w/p). She needs 15 pages. So first you have to find how many words she can type in one hour. 60 minutes in an hour, she can type 70 w/p.

60x70=4,200 words per hour (w/h).

Next you should find out how many words on 15 pages total.
350x15= 5,250.

I would put 4,200/5,250 as a fraction to gage how much she has left. She has most of it done already in ONE HOUR. Reduced, she has done 4/5s of the essay. Now you just need to get 1/5 of 5250, which is 1050.

She needs to do 1050 words. If one minute is 70, do 1050/70 which is 15.

The answer is 1 hour and 15 minutes.

I think... ;)