Quant/DI – Venn Diagrams

These type of questions can occur in both quant or DI depending on length and difficulty of the questions. 

I have a presentation made about Venn Diagrams, but I am a little under the weather and am unable to record narration right now. 

The slides are pretty self explanatory so I don’t think anyone will have a problem in understanding them. 

Here you have the presentation in .ppt format. It is only 88.5 Kb. 

Venn Diagrams Tutorial 

Here you go a screenshot of the presentation. 

Hope you like the tutorial! 

Exercise:

The exercise for similar problems such as the ones solved in the presentation are here.

The  file is in .doc format and is of 37 Kb. 

venn-diagrams-Exercise

Hope you like the post! 

Do come back for more!! 😀 

Your Say – Solution to Ruchi’s Problems

Ruchi asked me a doubt in Number Theory :

Hey thnx nicky
cud u pls temme the soln of the foll ques m nt able 2 solve it .

1234^1235^1236^1237 find the unit digit of this expression .

 

Here is the solution to her problem: 

Solution :

Method 1 – 

1234^1235^1236^1237 = (((1234)^1235)^1236)^1237

 

Now let’s consider the inner most terms -> (1234)^1235 

Using our method given in Number Systems Thoery , we get 

1235/4 gives us Rem = 3

So, last digit of (1234)^1235 = last digit of 4^3 which is 4

Now,

last digit of 

(((1234)^1235)^1236)^1237 is the same as last digit of (4^1236)^1237

 

Now, consider 4^1236 . Last digit of this can be obtained again by using the same technique 

remainder of 1236/4 is 0 , so last digit is last digit of 4^4 which is 6.

Now, similarly, we get  

that last digit of (((1234)^1235)^1236)^1237 is the same as last digit of (6^1237)

Again, we get remainder of 1237/6  as 1. 

So, last digit of(((1234)^1235)^1236)^1237 is last digit of 6^1 which is 6 .

The last digit of(((1234)^1235)^1236)^1237 is 6.

Method 2 – 

If we observe the following 

4*4 = 16

4*4*4 = 64

4*4*4*4 = XX6

4*4*4*4*4 = XX4

 

Therefore, we infer that

– 4 to power of even number gives last digit as 6.

– 4 to power of odd number gives last digit as 4.  

 

Now, we can find out last digit of

1234^1235^1236^1237 = 1234^(1235*1236*1237)

if we know whether 1235*1236*1237 is odd or even.   

As we know that odd * even = even , and 1236 is even, we get that 1234 is raised to even power. 

So, last digit of 1234 ^ even is 6 (from the observation above)

Last digit of 1234^1235^1236^1237 is 6. 

 

Thank you for the problem Ruchi – I enjoyed solving it! 

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I hope you liked the way I solved Ruchi’s  problem. If you have any easier method to solve it, do let me know. 

Logical Reasoning – Syllogisms

All Cats are Dogs

Some Dogs are Birds

How do you solve these questions in under a minute?

Check out the presentation here 🙂

It is in .ppt format and is 8 MB in size.

logical-deductions-Syllogisms

A sample presentation without narration is here on slideshare.net

I haven’t put it up here, ’cause it seems to be crashing the blog.

Here’s a screenshot of the presentation 🙂