Flying with the wind, a plane can travel 840 miles in 4 hours. Against the wind, the plane requires 5 hours to fly the same distance. Find the speed of the plane in calm air and the speed of the wind, both in miles per hour.

The answer you are looking for is right in front of you it’s c. 3/20

1.   an exact solution requires a radical solution - no decimal approximation.2. (a)4x^3 = 756x^3 = 756/4 = 189x =   cube root of 189 =   5.74   to nearest hundredth answer(b)   189 = 3*3*3*7   so we can write the cube root of 189 as 3∛7 answerchecking (a) 4*(5.74^3 =   756.48   which is very close(b)   4* ((3∛3)^3   = 4*189   = 756   - spot on! 3. i would use solution b because the original question asked for an exact solution.