Reply To: Puzzles
@RickOShea, nice little algebra problem.
Lets call the distance travelled in one direction d.
We also know that distance = speed x time and we are working in hours as knots = miles per hour
For journey 1, then d = 12.5 * t_1
For journey 2, then d = 10 * (t_1 + 2.5*24) = 10 * (t_1 +60) = 10*t_1 + 600 Note: two and a half days longer than journey 1 and there are 24 hours in a day
As the distance d is the same for both we can write that 12.5*t_1 = 10*t_1 + 600
Solving for t_1 gives (12.5-10) * t_1 = 600, t_1 = 600 / 2.5, therefore t_1 = 240 hours, or 10 days.
Journey 1 therefore was 12.5 * 240 = 3000 miles in 10 days
Checking, journey 2 was 10 * (240+60) = 3000 miles (as we would expect) in 12.5 days, or 2.5 days longer than journey 1.