The position of a moving ant is given by: r = (tsin(t), tcos(t), 1)
Find its speed.

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

Will give a: 122 b: 90 c: 48 d: 180

Paul can type 60 words per minute and jennifer can type 80 words per minutes. how does paul's typing speed compare to jennifer's