.
Let "r" be the rate of the slower train, in km/h/
Then the rate of the faster train is (r+20) km/h.
The "total distance equation" is
6r + 6*(r+20) = 1692 kilometers
6r + 6r + 120 = 1692
12r = 1692 - 120 = 1572 ====> r = = 131.
Answer. The slower train speed is 131 km/h. The faster train speed is 131+20 = 151 km/h.
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To see othes similar solved problems, see the introductory lessons on Travel and Distance
- Travel and Distance problems
- Travel and Distance problems for two bodies moving in opposite directions
- Travel and Distance problems for two bodies moving in the same direction (catching up)
in this site.