A man covers certain distance by his car, had he moved 6km/hr faster he would have taken 4 hours less, if he had moved 4km/hr slower he would have taken 4 hours more.Find the distance.
Please help with the approach

If there are options, I will use options. Failing that, I suspect trial and error will be quicker than solving equations. Still if you want equations:
s * t = (s + 6)*(t-4) = (s – 4)(t + 4)
Trial and error gave me 24 speed and 20 time (in around a minute), giving distance of 24 * 20 = 480.
regards
J

In the first question the answer comes out to be 12. This is the harmonic mean of 15 and 10. I don’t think this is just a coincidence. Could you please explain.

It isn’t a coincidence – it is because the times are in AM in this particular case. But it will not work for any random times…only if times are in AM will speeds be in HM and vice versa…

On this blog, we just have a few posts of vocabulary and so on; the focus was more on Quant. But you might try T’s blog at http://www.imschennai.in/blog/ , I am sure you will find plenty of useful stuff there!

A man covers certain distance by his car, had he moved 6km/hr faster he would have taken 4 hours less, if he had moved 4km/hr slower he would have taken 4 hours more.Find the distance.

Please help with the approach

If there are options, I will use options. Failing that, I suspect trial and error will be quicker than solving equations. Still if you want equations:

s * t = (s + 6)*(t-4) = (s – 4)(t + 4)

Trial and error gave me 24 speed and 20 time (in around a minute), giving distance of 24 * 20 = 480.

regards

J

In the first question the answer comes out to be 12. This is the harmonic mean of 15 and 10. I don’t think this is just a coincidence. Could you please explain.

It isn’t a coincidence – it is because the times are in AM in this particular case. But it will not work for any random times…only if times are in AM will speeds be in HM and vice versa…

regards

J

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Hello Sir,

This might be inappropriate ,but i would like to know if you have any such blog for Verbal.

Thanks,

Shivam

On this blog, we just have a few posts of vocabulary and so on; the focus was more on Quant. But you might try T’s blog at http://www.imschennai.in/blog/ , I am sure you will find plenty of useful stuff there!

regards

J