Quantitative Aptitude - Arithmetic Ability Questions

                                         A                  B                   C

investment                    3x                 4x                  5x

Rate of return              6y%              5y%                4y%

Return                        18xy100 20xy100 20xy100                

               Total = (18+20+20) = 58xy100

     B's earnings - A's earnings  = 2xy100 = 250

     Total earning = 58xy100 = 7250

Let A, B, C be the events of getting a white ball in first, second and third draw respectively, then 

 Required probability = PA∩B∩C 

= PA PBA PCA∩B

 Now, P(A) = Probability of drawing a white ball in first draw = 4/18 = 2/9

When  a white ball is drawn in the first draw there are 17 balls left in the urn, out of which 3 are white

 ∴PBA=317 

Since the ball drawn is not replaced, therefore after drawing a white ball in the second draw there are 16 balls left in the urn, out of which 2 are white.

 ∴PCA∩B =216=18

 Hence the required probability = 29×317×18=1204

At 5% more rate, the increase in S.I for 10 years = Rs.600  (given)

So, at 5% more rate, the increase in SI for 1 year = 600/10 = Rs.60/-

i.e. Rs.60 is 5% of the invested sum

So, 1% of the invested sum = 60/5

Therefore, the invested sum = 60 × 100/5 = Rs.1200

Let the height of the parallelogram be x. cm. Then, base = (2x) cm.

2x×x=72=>2x2=72=>x=6 

On carefully inspecting this question, one can understand that there are two days which are important and these are:

A. My Birthday.

B. The day when I am making this statement.

If you think for a while, you will understand that such statements can be made only around the year’s end. So, if my birthday is on 31 December, then I will be making this statement on 1 January.

I will further explain using the following example:

1. Consider that today is 01 January 2017.

2. Then, the day before yesterday was 30 December 2016 and according to the question I was 25 then.

3. Yesterday was 31 December 2016, which happens to be my birthday too (Woohoo!), and my age increases by one to become 26.

4. I will turn 27 on my birthday this year (31 December 2017).

5. I will turn 28 on my birthday next year (31 December 2018).

Now, if you read the question again, it will make more sense:

The day before yesterday(30 December 2016), I was 25 years old and next year(31 December 2018) I will be 28.