They say that smoking can reduce your life expectancy by 20%. If the life expectancy for a non-smoker is 90 years old, what is the life expectancy for a smoker?

How many square feet of out door carpet will we need for this hole? 8ft 3ft 12ft 4ft

1. the wheeling bridge in west virginia is about 307 meters long. if you walk with a stride of about meter, about how many steps would it take you to cross this suspension bridge?

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).