Quantitative Aptitude - Arithmetic Ability Questions

There are 12 - 3 = 9 patients.They can be seen in 12P9 = 79833600 ways

55 min. spaces are covered in 60 min.
60 min. spaces are covered in ((60/55) x 60) min = 720/11 min.
Loss in 65 min. = (720/11 - 65 ) = 5/11
Loss in 24 hrs = (5/11 x 1/65 x 24 x 60)min = 1440/143 min.

K x 3/8 = 141 => K = 376

376 x 32.08/100 = 120

Since order does not matter it is a combination. 

The word AND means multiply. 

Given 4 basketball, 3 volleyball, 2 soccer. 

We want 2 basketball games and 1 other event. There are 5 choices left. 

C(n,r) 

C(How many do you have, How many do you want) 

C(have 4 basketball, want 2 basketball) x C(have 5 choices left, want 1) 

C(4,2) x C(5,1) = (6)(5) = 30

Therefore there are 30 different ways in which you can go to two basketball games and one of the other events.

1/2 as a percentage means

1/2 = 0.5 in decimal

Now, in percentage means 0.5 x 100% = 50%.

Given total number of boys in the school = 1500

In that 35% are Hindu, 30% are Sikh, 15% are Muslims

=> 35 + 30 + 15 = 80%

Remaining Boys = 100% - 80% = 20% of 1500

=> 20 x 1500/100 = 300 boys are Christians. 

Let marks obtained by N = x

M's marks = 0.80x

L's marks = 1.25 (0.80x)

K's marks = (0.90) (1.25) (0.80x)

= 0.9x

But 0.9x = 360 ⇒ x = 400

Percentage of Marks obtained by N

= 400 x 100/500 = 80%

After day 1, A finishes 1/9 of the work.

After day 2, B finishes 1/7 more of the total work. (1/9) + (1/7) is finished.

After day 3, C finishes 1/5 more of total work. Total finished is 143/315.

So, after day 6, total work finished is 286/315.

Now remaining work =  29 /315

On day 7, A will work again 

Work will be completed on day 7 when A is working. He must finish 29/315 of total remaining work.

Since he takes 9 days to finish the total task, he will need 261/315 of the day. 

Total days required is 6 + (261/315) days.