Maths
Maths Puzzle
Numerical Ability
Walking (6/7)th of his usual speed, a man is 12 minutes too late.
The usual time taken by him to cover that distance is:
Read Solution (Total 4)
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- Let us consider the usual speed=x meters/second,time=t seconds and distance=d meters.If the speed is equal to x,the man reaches the distance d in t seconds.
Therefore x=(d/t).
Now if the man travels with (6/7)th of his usual speed,the man is 12 minutes late i.e., when speed=(6/7)x meters/second,time=[t+(12*60)]seconds.
Therefore (6/7)x=d/(t+720),but x=(d/t)
therefore (6d/7t)=d/(t+720),solving this we get 6(t+720)=7t which implies t=720*6=4320 seconds i.e., t=72 minutes. - 10 years agoHelpfull: Yes(1) No(0)
- 6/7th of usual speed means time taken will be 7/6th of usual time...
Therefore New time= 7/6th of usual time...
New time- usual time= 7/6-1
=1/6
So 6*12=72mins - 10 years agoHelpfull: Yes(1) No(0)
- x-6x/7=12
x=12*7
x=84min
- 10 years agoHelpfull: Yes(0) No(1)
- if x= original speed & y=original time
then
x------>y
6x/7------>y+12
so difference in speed=x/7 is equivalent to 12 min
thus, x=12*7=84
since distance remains same in this both cases,
xy=6x/7(y+12)
x=84
so, y=72(reqd time) - 10 years agoHelpfull: Yes(0) No(0)
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