Quantitative Aptitude - Arithmetic Ability Questions

On straight line means 180 degree angle.
180 = 11/2 min – 30 hrs
180 = 11/2 m – 30 × 3
180 = 11/2 m – 90
(180 + 90) 2 = 11 m
m = 540/11 = 49 1/11 minutes.

Let the two parts be Rs. x and Rs. (1301 - x).

 x1+41007=1301-x1+41009

 x1301-x=1+41002=2625*2526

=> 625x=676(1301-x) 

1301x=676 x 1301x=676.
So,the parts are rs.676 and rs.(1301-676)i.e rs.676 and rs.625

Let 4 girls be one unit and now there are 6 units in all.

They can be arranged in 6! ways.

In each of these arrangements 4 girls can be arranged in 4! ways. 

Total number of arrangements in which girls are always together = 6! x 4!= 720 x 24 = 17280

Average =   (76 + 65 + 82 + 67 + 85 )/ 5 = 375/5   =  75.

Manager's monthly salary Rs. (1600 * 21 - 1500 * 20) = Rs. 3600.

Ratio of times taken by A and B = 100 : 130 = 10 : 13.
Suppose B takes x days to do the work.

Then, 10 : 13 :: 23 : x     =>     x = ( 23 x 13/10 )     =>     x = 299 /10.

A's 1 day's work = 1/23 ;
B's 1 day's work = 10/299 .

(A + B)'s 1 day's work = ( 1/23 + 10/299 ) = 23/299 = 113 .

Therefore, A and B together can complete the work in 13 days. 

Distance covered in one revolution = 88×10001000= 88m. 

2πR2=88 ⇒2×227×R=88 ⇒R=88×744