Quantitative Aptitude - Arithmetic Ability Questions

Let the number of boys in the group originally be x.
Total weight of the boys = 30x
After the boy weighing 35 kg joins the group, total weight of boys = 30x + 35
So 30x + 35 + 31(x + 1) = > x = 4.

Here always remember, when ever x% loss,
it means S.P. = (100 - x)% of C.P
when ever x% profit,
it means S.P. = (100 + x)% of C.P

So here will be (100 - x)% of C.P.
= 80% of 1200
= (80/100) * 1200
= 960

On dividing we get

75)8485(113
     75
     ------
       98
       75
      ------
       235
       225
      ------
         10
      ------
Required number = (8485-10)=8475.

Part filled by (A + B) in 1 minute = (1/60 + 1/40) = 1/24
Suppose the tank is filled in x minutes.
Then, x/2(1/24 + 1/40) = 1
(x/2) * (1/15) = 1 => x = 30 min.

It is given that efficiency ratio =3:1

so time ratio will be 1:3 (since work is same)

Also given that time diff = 32 days. ratio difference = 3-1 =2 

2 ratio = 32 days

1 ratio = 16 days.

So A will alone finish it in 16 days and B will finish it in 16*3 = 48 days.

Total work = LCM of 16 and 48 = 48.

Total time = Total work/Total efficiency 

ie; 48/4= 12 days.

F = Rs. 2160

TD = Rs. 360

PW = F - TD = 2160 - 360 = Rs. 1800

True Discount is the Simple Interest on the present value for unexpired time

=>Simple Interest on Rs. 1800 for unexpired time = Rs. 360

Banker's Discount is the Simple Interest on the face value of the bill for unexpired time

= Simple Interest on Rs. 2160 for unexpired time

=(360/1800)* 2160

= (1/5) * 2160

=Rs. 432

Let Kumar’s present age be "x" years and Sailesh’s present age be "y" years.
Then, according to the first condition,

x - 10 = 3(y - 10) => x - 3y = - 20 ........(1)

Now, Kumar’s age after 10 years = (x + 10) years.

Sailesh’s age after 10 years = (y + 10) years.

(x + 10) = 2 (y + 10)  => x - 2y = 10 ......(2)

Solving (1) and (2),

we get x = 70 and y = 30

Kumar’s present age = 70 years    and  Sailesh’s present age = 30 years.