Quantitative Aptitude - Arithmetic Ability Questions

From the information provided we know that,

Principal + 8% p.a. interest on principal for n years = 180 …….. (1)

Principal + 4% p.a. interest on principal for n years = 120 ……… (2)

Subtracting equation (2) from equation (1), we get

4% p.a. interest on principal for n years = Rs.60.

Now, we can substitute this value in equation (2),

i.e Principal + 60 = 120

= Principal = Rs.60.

We know that SI = , where p is the principal, n the number of years and r the rate percent of  interest.

In equation (2), p = Rs.60, r = 4% p.a. and the simple interest = Rs.60.

Therefore, 60 =(60*n*4)/100

=> n = 100/4 = 25 years.

Let each instalment be Rs.x .

1st year =  [x + (x * 12 * 2)/100] 

2nd year = [ x + (x *12 * 1)/100] 

3rd year = x 

Then, [x + (x * 12 * 2)/100] + [ x + (x *12 * 1)/100] + x =1092 

3x + ( 24x/100 ) + ( 12x/100 )  = 1092 

336x =109200

Therefore, x = 325 

Each instalment = Rs. 325

Let the sum at 15% be Rs x and that at 18% be Rs (24000 - x).

{(x * 15 * 1)/100 } + { [(24000 – x) * 18 * 1]/100 } = 4050

or 15 x + 432000 - 18x = 405000 or x = 9000.

Money borrowed at 15% = Rs 9000 .

Money borrowed at 18% = Rs 15000.

Let sum = X. Then S.I = 16x/25

Let rate = R% and Time = R years.

Therefore,  (x * R * R)/100 = 16x/25   =>  R = 40/5 = 8

Therefore, Rate = 8% and Time = 8 years.

Let sum = P and original rate = R. Then

[(P * (R+2) * 3)/100] - [ (P * R * 3)/100] = 360

3P*(R+2) - 3PR = 36000

3PR + 6P - 3PR = 36000

6P = 36000

P = 6000

S.I. for 1 ½ years = Rs (1164 - 1008) = Rs 156 . 

S.I. for 2 years = Rs (156 x 23 x 2)= Rs 208. 

Therefore, Principal = Rs (1008 - 208) = Rs 800. 

Now, P = 800, T= 2 and S.I. = 208.

Therefore, Rate = (100 x S.I.) / (P x T) = [ (100 x 208)/(800 x 2)]% = 13%

Let principal = P, Then, S.I.= P and Time = 8 years

We know that S.I. = PTR/100

Rate = [(100 x P)/ (P x 8)]% = 12.5% per annum.

 Let sum be Rs.x then, S.I. =Rs. [ x * (27/2) * 4 * (1/100) ] = Rs. 27x/50 

Amount =Rs [ x + (27x/50)] = Rs.77x/50 

=> 77X/50 = 2502.50  

=>X= (2502.50 * 50)/77 = 1625 

Hence Sum = Rs.1625