Find r(t) if r'(t)=ti+e^tj+te^tk and r(0)=i+j+k

What is the approximate total length of iron edging needed to create the square frame and the two diagonals?

Leo is going to use a random number generator 4 0 0 400 times. each time he uses it, he will get a 1 , 2 , 3 , 4 , 1,2,3,4, or 5 5. what is the best prediction for the number of times that leo will get an odd number?

If the measure of xyz is 81 what is the measure of yz