v tuf prob

This is you called tough? Strange!!!!

What is the first common multiple of 5 and 7?
Answer 35.

So, in the given number line, replace the 1 with 35. Now mark the 1/5ths and 1/7ths position in the number line.

1/7ths position will be: 5, 10, 15, 20, 25, 30 and 35.

1/5ths positions will be: 7, 14, 21, 28 and 35.

So your number line will be: 0, 5, 7, 10, 14, 15, 20, 21, 25, 28, 30, 35.

Now where is least difference between two numbers in the above number line?

Answer: (i) between 14 and 15, (ii) between 20 and 21.
That least distance = 1.

Now initially you have multiplied the number line with 35. Now divide the least distance with 35 to get the correct value.

So answer is 1/35.

thanks bt i still cldnt get it...can u explain in some better way
1/7 = 5,10,15...how cm

Hi Vivek,

If you start writing down the 1//5 ths and 1/7 ths given on the number line
you will get

1/7,1/5,2 /7,2/5,3/7,4/7,3/5,5/7,4/5,6/7

Now we have to find the least value between any 2 of the tick marks represented by the numbers above. With fractiosn its easier to compare if you can get teh denominators to match by finding the LCM.

The LCM is 35

So we get

5/35,7/35,10/35,14/35,15/35,20/35,21/35,25/35,28/35.30/35

A fraction gives the least value when the numerator is as small as possible and the denominator as big as possible.

In the list above 15/35 - 14/35 = 1/35 gives the least distance which is other way of saying that these tick marks are closer to each other than any other on the list(least distance between them)

Hope this helps!

vivek.kapoor83 wrote:thanks bt i still cldnt get it...can u explain in some better way
1/7 = 5,10,15...how cm

Look. I asked to get the common multiplier of 7 and 5. Why? because we have divide the number line in 1/7th and 1/5th parts.

So let's take the example of 1/5th series.

1/5, 2/5, 3/5, 4/5, 1.

Now as we have multiplied the series with common multiplier so new series would be:

= 35 * 1/5, 35 * 2/5, 35 * 3/5, 35 * 4/5, 35 * 1.
= 7, 14, 21, 28, 25

I guess now you easily write series for 1/7 and later on merge both the series.

Easy!!!