2. Questions Bank
  3. SSC
  4. Quantitative Aptitude
  5. Speed, Time and Distance

SSC Quantitative Aptitude Speed, Time and Distance Question Bank Speed Time and Distance (II)

  • question_answer
    By how much per cent must a motorist increase his speed in order to reduce the time by 20%, taken to cover a certain distance?

    A) 20

    B) 25

    C) 30

    D) None of these

    Correct Answer: B

    Solution :

    [b] Distance \[=(\text{Time}\times \text{Speed})=t\times x.\] Let the "required increases in speed be p%. Then, \[(80%\,\,of\,\,t)\times \frac{(100+p)}{100}\times x=t\times x\] \[\Rightarrow \]   \[\frac{80}{100}\times t\times \frac{(100+p)}{100}\times x=t\times x\] \[\Rightarrow \]   \[\frac{4(100+p)}{500}=1\]\[\Rightarrow \]\[4p=100\] \[\Rightarrow \]               \[p=25\] \[\therefore \] Required increase in speed             \[=25%\]


You need to login to perform this action.
You will be redirected in 3 sec spinner