A runner can run 20 miles in 150 mins if she runs at that speed what is her pace in mins per mile

The probability that you roll a two on a six-sided die is 1 6 16 . if you roll the die 60 times, how many twos can you expect to roll

I'm confused on this could anyone me and show me what i need to do to solve it.

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .