Quantitative Aptitude - Arithmetic Ability Questions

Let the original number be x.

Final number obtained = 110% of (90% of x) =(110/100 * 90/100 * x) = (99/100)x. 

x-(99/100)x=10

=> x =1000

Let the required length be x meters

 More men, More length built     (Direct proportion) 

Less days, Less length built      (Direct Proportion)

Men20:35Days6 : 3⋮⋮ 56 :x 

=> (20 x 6 x X)=(35 x 3 x 56) 

=> x = 49 

Hence, the required length is 49 m.

When R and W are the first and last letters of all the words then we can arrange them in 5!ways. Similarly When W and R are the first and last letters of the words then the remaining letters can be arrange in 5! ways.

Thus the total number of permutations = 2 x 5!  = 2 x 120 = 240

Given numbers are 1.08 , 0.36 and 0.90

 H.C.F of 108, 36 and 90 is 18                  [ ∵ G.C.D is nothing but H.C.F]

 Therefore, H.C.F of given numbers = 0.18                 

Explanation:

Let rate = R% and time = R years.

Then, 1200*R*R100=432

12R2=432

=>R2=36⇔R=6

Excess of B's height over A's = [(40/(100 - 40)] x 100% =  66.66%

Given number series is 514   470   ?   415   404

Here the pattern it follows is

514

514 - 44 = 470

470 - 33 = 437

437 - 22 = 415

415 - 11 = 404

Hence, the missing number in the given number series is 437.