Quantitative aptitude problem

CA 595 views 5 replies

1). in ------------ years a sum will double at 5% p.a.compound interest.

a). 15yrs3months,                                                                                                                                                 b).14yrs2monts,             c).14yrs3month                                                                                                                                                      d). 15yrs2months.

 

2). the sum of a certain number of terms of an ap series -8,-6,-4,......................is 52.the no.of terms is 

a).12                                                                                                                                                                          b).13

c).11                                                                                                                                                                           d).none.

 

3). on the avg experienced person does 5 units of work while a fresh one 3 units of work daily but the employer has to maintain an output of at least 30 units of work per day.tis situation can be expressed as 

a).5x+3yless30.                                                                                                                                                   b).5x+3ygreater30

c).5x+3y less than equal to 30                                                                                                                           d).none.

 

4). integrate(4,2)(3x-2)^2dx and the value is

a).104                                                                                                                                                                       b).100

c).10                                                                                                                                                                          d).none.                                                                     

Replies (5)

1. let the principle be x

2x= x {1+ 5/100} to the power n 

Substitute the given options to find the most appropriate answer. May require scientific calculator. option c is correct.

{1+.05} upto 14 powers and then you might get something 1.97.. or so. Next check for 1+ .05 * 2/12 or 3/12 as per option b and c. Then multiply it with the 1.97... something.

 

sum = n/2 { a+(n-1)d}

52= n/2 { -8 + (n-1) 2}           a= -8, d= 2nd term- 1st term= -6+8 =2

52= n { -4 + (n-1)}

Apply the given choices. May be none. I m not pretty sure.

3. Being particular, option d probable.

5x+3y greater than or equal to 30

i cant understand question no .1 at the side of cheking.

For question number 1 and any question of this type, you always make sure to try in ascending or descending order of the numbers given in the question. In the question 1, you have 14 and 15 yrs with two-two different choices. So first you apply the formula of compound interest:

Sum= p{1+i} to power of n

where i is rate of interest; 5/100= .05

n= number of years

P is principal. 

So, as i have considered the principal to be x, 

2x= x{ 1+.05} to the power of n

2= { 1+ .05}      { being x cancelled as common on both sides}

After this just apply, the choice, i.e first 14 years, then you may get something in decimal, 1.97..... now check for b and c options as i have shown above.

rate of interest * 14 years * 2/12 or 

rate of interest * 14 years * 3/12

Now, multyiply both options with 1.97... and then check which one satisfies the equation more appox. 14 years 3 months is correct.


CCI Pro

Leave a Reply

Your are not logged in . Please login to post replies

Click here to Login / Register