Question

A jet travels from Chicago to Kansas City at a speed of 440 knots. If it takes a plane 3 hr longer to fly from Kansas city to Chicago at a speed of 110 knots what is the distance between the two city’s

Answer 1

Chicago to KC

d = ??

v = 440 knots

t = t - 3

KC to Chicago

d = ?? But it is the same distance as the givens above.

v = 110 knots

t = t hours

Equation

d = r * t

Solve

Since the distances are the same you can equate the r * t

440 * (t - 3) = 110 * t The numbers would be a lot smaller if you divided both sides by 110

[440 * (t - 3)] / 110 = 110 t / 110

4*(t - 3) = t Remove the brackets.

4t - 12 = t Subtract t from both sides

3t - 12 = 0 Add 12 to both sides

3t = 12 Divide by 3

t = 12/3

t = 4 The time to fly for the slower plane = 4 hours.

Solve for distance.

d = r * t

d = 110knots / hr * 3 hr

d = 440 knots. You should get exactly the same thing for t if you do not divide by sides by 110 knots

440 * (t - 3) = 110*t

440 f - 440 * 3 = 110*t

440t - 1320 = 110t Subtract 110t

440t - 110t - 1320 = 0

330t - 1320 = 0

330t = 1320

t = 1320 / 330

t = 4 Same answer.