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Question
Two trains start simultaneously. The first train moves from A to B, whereas the second train moves from B to A. After they meet at a point in between, they respectively take 144 hours and 4 hours to reach their destinations. What is the ratio of their speeds?
A
${1/6}$.
B
${7/5}$.
C
${13/8}$.
D
${19/8}$.
Soln.
Ans: a
Ans: a
If they take $t_1 and t_2$ hours respectively to reach their destinations, then the ratio of their speeds is $√t_2 : √t_1$. So we get $√4 : √144$, which gives 2 : 12, or ${1/6}$.