Quantitative Aptitude - Arithmetic Ability Questions

Here the number of cogs is inveresly proportional to number of revolutions

=> More cogs less revolution
=> 6 : 14 :: x : 21
=> (21x6)/14 = 9

P( only one of them will be selected) = p[(E and not F) or (F and not E)] 

 = PE∩F∪F∩E 

= PEPF+PFPE

 =17×45+15×67=27

Number of pages typed by Adam in 1 hour = 36/6 = 6
Number of pages typed by Smith in 1 hour = 40/5 = 8
Number of pages typed by both in 1 hour = (6 + 8) = 14
Time taken by both to type 110 pages = (120 * 1/14) = 847 = 8 hrs 34 min.

Total age of 10 students = 150 years

Total age of 15 students = 240 years

Total age of 5 new students = 240 - 150 = 90 years

 Average age of 5 new students = 90/5 = 18 years.

Let 'd' be the distance between A and B
K -time = d/10 + d/9 = 19d/90 hours
L -time = 2d/12 = d/6 hours
We know that, 10 min = 1/6 hours
Thus, time difference between K and L is given as 10 minutes.
=> 19d/90 - d/6 = 1/6
=> (19d-15d)/90 = 1/6
=> 4d/90 = 1/6
Thus,
d= 15/4 km = 3.75 km.

hence the distance between A and B is 3.75 km.

Given ratio of number of sheep and horses = 4 : 15
Let number of sheep and horses are 4k and 15k
Number of horses = 13200/110 = 120
Now 15K = 120 and k = 8
Number of sheep = 4k = (4 x 8) = 32

The servant worked for 9 days instead of 12 days, he should receive 9/12 of his total payment

Let the price of 1 shirt be Rs. S 

i.e., 3/4 (400 + S).

However, the question states that the servant receive Rs. 280 + S where S is the price of the shirt.

By equating the two equations we get 3/4 (400 + S) = 280 + S.

Therefore, Price of the shirt S = Rs. 80.

First we need to choose two vowels 3C2 and then three consonants 5C3. Now that we have 5 letters required to make the word,arrange them in 5! ways.

So,3C2*5C3*5! = 3600