Quantitative Aptitude - Arithmetic Ability Questions

In one day work done by K = 1/20

Work done by K in 2 days = 1/10

Work done by K,L,M on 3rd day =1/20 + 1/30 + 1/60 = 1/10

Therefore, workdone in 3 days is = 1/10 + 1/10 = 1/5

1/5th of the work will be completed at the end of 3 days.

The remaining work = 1 - 1/5 = 4/5

1/5 of work is completed in 3 days

Total work wiil be done in 3 x 5 = 15 days.

Ans. C.
Let 4 consecutive even numbers are x, x+ 2, x+ 4, x+ 6
According to the question -
1/x + 1/x+2 = 11/60
x+2+x/ x(x+2) = 11/60
2(x+1)/x^2 + 2x = 11/60
120x + 120 = 11x 2 + 22x
11x 2 - 98x – 120 = 0
So ,
X = -24/22 , 10
X = -12/11 , 10
So, the numbers will be 10,12,14,16.
Hence,
Third largest number = 14
Reciprocal of third number = 1/14

Since floor starts form the 1 therefore 2 will be the 1st floor.
Form 1 to 10 only 4,6,8,9,10 are not prime.
Form 11 to 20 only 14 ,16,18 are not prime also non of their digits are prime.
From 21 to 30 each number has a prime number so it must no be consider.
In between 40 to 49 we have to consider only 40,44,46,48,49.
50 to 59 follow either of the condition so we have too neglect it.
In between 60 to 68 60,64,66,68.
total option = 17.

Given   1.21x0.91.1x0.11

= 1.21x100x0.9x101.1x10x0.11x100

= 9

= 3.

sin 46. cos 44+ cos 46. sin 44

sin 46. sin (90 -44)+ cos 46. cos (90 -44)

= sin^2 46 + cos^2 46

= 1

Total number of balls = 2 + 3 + 4 = 9

Total number of ways 3 balls can be drawn from 9 = 9C3

No green ball is drawn = 9 - 3 = 6 = 6C3

Required number of ways if atleast one green ball is to be included = Total number of ways - No green ball is drawn

= 9C3 - 6C3

= 9x8x7/3x2  -  6x5x4/3x2

= 84 - 20

= 64 ways.

Here,n = 4(children)

P(girl)= 0.5

P(of atleast one girl)= 1 - P(no girls)

                             = 1 - 0.0625 = 0.9375

Three digit number will have unit’s, ten’s and hundred’s place.

Out of 5 given digits any one can take the unit’s place.

This can be done in 5 ways. ...              (i)

After filling the unit’s place, any of the four remaining digits can take the ten’s place.

This can be done in 4 ways. ...              (ii)

After filling in ten’s place, hundred’s place can be filled from any of the three remaining digits.

This can be done in 3 ways. ... (iii) 

So,by counting principle, the number of 3 digit numbers = 5x 4 x 3 = 60