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Helen travels from P to Q at x km/hr and then from Q to R at (x + 6) km/hr. The distance from P to Q is 40 km while from Q to R is 100 km. If the to time taken between P and Q is the same as the one taken between Q and R, find

      

Helen travels from P to Q at x km/hr and then from Q to R at (x + 6) km/hr. The distance from P to Q is 40 km while from Q to R is 100 km. If the to time taken between P and Q is the same as the one taken between Q and R, find
i) Her speed between Q and R
ii) The total time taken to complete the journey

  

Answers


John
i) Time = $\frac{Distance}{Speed}$

Time taken to travel from

P to Q is $\frac{40}{x}$ hrs. Time taken to travel from Q to R is $\frac{100}{x + 6}$

If the two times are equal then

$\frac{40}{x}$ = $\frac{100}{x + 6}$

40x + 240 = 100x

240 = 60x, x = 4

the speed between Q and R is

(x + 6) = 4 + 6 = 10km/hr

ii) Total time taken is

$\frac{Total distance}{Total speed}$ = $\frac{40}{4} + \frac{100}{10}$

= 20 hours
johnmulu answered the question on March 6, 2017 at 11:47


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