CAT Questions

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The number of points of intersection of 37 lines is C237. But 13 straight lines out of the given 37 straight lines pass through the same point A.

Therefore instead of getting C213 points, we get only one point A. Similarly 11 straight lines out of the given 37 straight lines intersect at point B. Therefore instead of getting C211 points, we get only one point B.

 Hence the number of intersection points of the lines is C237-C213-C211 +2 = 535

The given number puzzle can be soved in two ways.

Logic 1 ::

Row 1  - 2 x 3 = 6 , 6 x 3 = 18

Row 2  - 4 x 5 = 20 , 20 x 5 = 100

Row 3  - 3 x 7 = 21 , 21 x 7 = 147

Hence, the missing number could be 3.

Logic 2 ::

Row 1 - 6 x (2+1) = 18

Row 2 - 20 x (4+1) = 100

Row 3 - 21 x (6+1) = 147

Hence, the missing number could be 6.

Therefore, 3 or 6 is the right answer.

Detailed description of a man's life is Biography.

Similarly, detailed description of a Nations is called History.

The quadratic equation whose roots are reciprocal of 2x2+5x+3=0 can be obtained by replacing x by 1/x.

Hence, 2(1/x)(1/x)+ 5(1/x) + 3 = 0

=> 3x2+5x+2=0

The given number series is 1 8 36 ? 1100 7701

It follows a pattern that,

1

1 x 3 + 5 = 8

8 x 4 + 4 = 36

36 x 5 + 3 = 183

183 x 6 + 2 = 1100

1100 x 7 + 1 = 7701

Hence, the missing number in the given series is 183.

As Tennis is a kind of Sport, similarly, Chemistry is a kind of science.

Hence, Tennis : Sport :: Chemistry : Science.

The pattern is -4, +9,-16, +25, -36

The next number=119+49=168