CAT Questions

---

3, 7, 6, 5, 9, 3, 12, 1, 15, ... has two different series

1) 3, 6, 9, 12, 15.....

2) 7, 5, 3, 1, .....

-1 is the next number.

Given series is 372, 823, 644, 582, 46?, 8?7

Here the series follow the rule that :
372 = 3+7+2 = 12
823 = 8+2+3 = 13
644 = 6+4+4 = 14
582 = 5+8+2 = 15
46? = 4+6+? = 16 => ? = 6
8?7 = 8+?+7 = 17 => ? = 2

So the missing numbers are 6 and 2

Here the given series follows a pattern that, multiplying the number with odd numbers in decreasing order starting with 13. That is,

6 × 13 = 78

65 × 11 = 858

858 × 9 = 7722

7722 × 7 = 54054

54054 × 5 = 270270

Hence, the wrong number is 54055

The given number series is 22, 11, 33, 16.5, 49.5, ?

22

22 / 2 = 11

11 x 3 = 33

33 / 2 = 16.5

16.5 x 3 = 49.5

49.5 / 2 = 24.75

Hence, the next number series is 24.75.

The given number series is 96, 95, 87, 78, ? 

It follows a pattern that,

$$\begin{gathered} 96 \\ 96 - 12 = 95 \\ 95 - 23 = 95 - 8 = 87 \\ 87 - 32 = 87 - 9 = 78 \\ 78 - 43 = 78 - 64 = 14 \end{gathered}$$

Hence, the next number in the given number series is 14.

Here the given number series is 5  11  21  44  ?  175

Now the given series follows a pattern, that

x2 + 1, x2 - 1, x2 + 2, x2 - 2, x2 + 3, x2 - 3,...

Then the missing number is x2 - 2

= 44 x 2 - 2 = 88 - 2 = 86

Hence, the missing number in the number series is 86.

Let the two conditioners be A and B

'A' cools at 40min

'B' at 45min

Together = (a x b)/(a + b)

= (45 x 40)/(45 + 40)

= 45 x 40/85

= 21.1764

= 22 min (approx).

1 x 1 + 1 x 1 = (1 + 1) = 2

2 x 2 + 2 x 2 = (4 + 4) = 8

8 x 3 + 3 x 3 = (24 + 9) = 33

33 x 4 + 4 x 4 = (132 + 16) = 148

148 x 5 + 5 x 5 = (740 + 25) = 765.