# Learning to Learn Math – II

We did the first webinar in this series —  Weighted Averages, a while ago, and it is time for the second one.

This webinar — The Beauty of Ratios — is devoted to using ratios them maximally in Arithmetic.

Those scoring above 70 might find some of the things discussed very elementary.

Those scoring below 35 might find some of the things discussed very scary.

But irrespective of scores, it ideal for those who are looking to take their skills on Time, Speed, Distance & Work, to the next level.

1. Afreen says

Greetings sir,
I have watched this video and found it extremely helpful so thank you so much for making this one. But I kinda had a query. Sir, what about questions like, 4 men can do a job in x days, 6 women in y days ,3 boys in z days and then their efficiencies in terms of each other is given and we are asked to find number of days taken by a men,b women and c boys?
How do I use ratio in these kind of questions like I find these kinda questions extremely lengthy. So is there any shorter way or so??

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• Hi Afreen,

Glad you found the webinar useful.

These problems are slightly long but not very. The Time and Work Concept & Application videos in the LEARN Module should have methods to tackle them.

I have never used ratios to tackle them but have relied on the patterns of the numbers to see if there is a faster way out.

You can use ratios by converting everything into 1 person and then using efficiencies — 4 men, x days, 1 man 4x days, similarly 1 woman, 6y days and use ratios from there on to express one in terms of the other.

Hope this helps,

All the best!

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2. Afreen says

Sir, is there any faster way of solving questions like these, instead of making all the equations :
Train A travelling at 63 kmph takes 27 to sec to cross Train B when travelling in opposite direction whereas it takes 162 seconds to overtake it when travelling in the same direction. If the length of train B is 500 meters, find the length of Train A.
Thank you.

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• Well, the fastest way to do this is to use ratios, since time becomes 6 times — 27 to 162 — speed has to become 1/6.

So (63-x) = (63+x)/6, x = 45.

From here it’s very simple — just one calculation — (45+63)*(5/18)*27 – 500 = 310

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