Given the geography of this area, do you think egypt was vulnerable to foreign invaders? explain your thinking.

I think that Egypt was actually very easily defended from foreign invaders. Most of all, it was protected by the desert on three sides, which made it impossible to attach Egypt  from any direction other than the north.

Then while invading Egypt from the North, one would have to go along the Nile: which can also be easily defended, so the invader would be easily stopped.

1190 is your answer! the way you get it is 1400 - 15% =1190 : )