Under the same power, it takes 4 hours for a meter to walk a word and 6 hours for b meter to walk a word. How much slower is B meter than A meter?
Solution: A meter 1/4 word 0 hour, B meter 1/6 word 0 hour.
M B is slower than M A (1/4-1/6) ÷ (1/4) =1/3.
10÷( 1/6)=60 hours (1/4)*60= 15 words.