Quantitative Aptitude - Arithmetic Ability Questions

Let the required number days be x.

Less spiders, More days (Indirect Proportion)

Less webs, Less days (Direct Proportion)

 Spiders1:7Webs7:1⋮⋮ 7:x 

=> 1 * 7 * x = 7 * 1 * 7 

=> x= 7

Given number series is 9 17 11 19 13 

Here the pattern is

• 9

• 9 + 8 = 17

• 17 - 6 = 11

• 11 + 8 = 19

• 19 - 6 = 13

• 13 + 8 = 21

• 21 - 6 = 15

• 15 + 8 = 23

Total number of balls = (8 + 7 + 6) = 21.

Let E = event that the ball drawn is neither red nor green 

            = event that the ball drawn is blue.

n(E) = 7.

P(E) = n(E)/n(S) = 7/21 = 1/3.

Given series is 

12        16         32          68         ?

Here it follows a pattern that,

12

12 + (2x2) = 16

16 + (4x4) = 32

32 + (6x6) = 68

68 + (8x8) = 132

There are total 9 letters in the word COMMITTEE in which there are 2M's, 2T's, 2E's.

The number of ways in which 9 letters can be arranged = 9!2!×2!×2! = 45360

There are 4 vowels O,I,E,E in the given word. If the four vowels always come together, taking them as one letter we have to arrange 5 + 1 = 6 letters which include 2Ms and 2Ts and this be done in 6!2!×2! = 180 ways.

In which of 180 ways, the 4 vowels O,I,E,E remaining together can be arranged in 4!2! = 12 ways.

The number of ways in which the four vowels always come together = 180 x 12 = 2160.

Hence, the required number of ways in which the four vowels do not come together = 45360 - 2160 = 43200

The given number series follows a pattern that,

56

56 + 8 = 64

64 - 16 = 48

48 + 32 = 80 (Not equal to 90)

80 - 64 = 16

16 + 128 = 144 

Hence, the odd number in the given number series is 90.

(150 x 460)/100 + (24 x 650)/100

= 690+156

= 846