CAT Questions

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Given that,

1st train speed = 62 km/hr 

2nd train speed  = 44 km/hr

Hence the relative speed of two trains is : 62-44 = 18 km/hr = 18×518 m/s = 5 m/s.

There fore, the first train crosses the second train i.e (85+75)mts of distance with a speed of 5m/s in, 

time = distancespeed = 85+755 = 32 sec.

From the assumption and trial and error method,

last three digits sum must leave the same digit as the answer. It is possible only if the answer must be units digit number leaving tens digit as carry.

And the possible 3rd digit is 5. Since 5 + 5 + 5 = 15 

Now, 2nd step is  1 + x + x + x = 5

=> 3x = 4

It is possible with x = 8. 8 + 8 + 8 + 1 = 25 leaving 2 as carry. 

Now, 3rd step is 2 + x + x + x = 5 => x = 1

Hence, the three dgits are 1, 8, 5.

185 + 185 + 185 = 555. 

The simple machine Axe is made up of both the lever arm and a wedge.

Given 

1 = 1 => 1 x 11 = 11

2 = 22 => 2 x 11 = 22

3 = 33 => 3 x 11 = 33

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Similarly,

11 => 11 x 11 = 121.

The main component of bones and teeth is Calcium Phosphate.

First nationalisation of commercial banks in India took place in 1969 and second time in 1980.

Let the sum be Rs.x. Then, 

 x1+101002-x=1155

⇒x11102-1=1155

=> x =5500

sum = Rs. 5500.

So, S.I = Rs. 5500×5×4100 = 1100

Here in the given puzzle,

2 x (2 + 2) = 8

3 x (3 + 3) = 18

4 x (4 + 4) = 32

5 x (5 + 5) = 50

Similarly,

6 x (6 + 6) = 72.