Quantitative Aptitude - Arithmetic Ability Questions

Let 'Y' be the youngest player.

The last song can be sung by any of the remaining 3 players. The first 3 players can sing the song in (3!) ways.

The required number of ways = 3(3!) = 4320.

Given letters are k, l, m, n, o = 5

number of letters to be in the words = 3

Total number of words that can be formed from these 5 letters taken 3 at a time without repetation of letters = 5P3 ways.

⇒ 5P3 = 5 x 4 x 3 = 60 words.

At least one black can be chosen in two ways from each box:
Now, probability of choosing at least one black ball from first box 

= 1/2 × [ (2C1× 2C1)/4C2 + 2C2/ 4C2 ]= 5/12

Probability of choosing at least one black ball from 2nd box
= 1/2 × [(4C1×12C1)/16C2 + 4C2/ 16C2] = 9/40

Final probability

= 5/12 + 9/40 = (50 + 27)/120 = 77/120

Let the monthly salary of Shankar be = Rs.x
Amount invested on expenditure = 25% = x/4;
Remaning amount = 3x/4;
Amount invested on children education = 20% i.e = 3x/20;
Remaining amount = 3x/4 - 3x/20 = 3x/5;
Remaining amount invested in three different schemes i.e is 1/3(3x/5)
=> x/5 = 5600
Therefore x = 28000
Hence, Monthly salary of Shankar is Rs. 28,000.

Let the second & third numbers are 2x & 3x respectively.
ATQ,
5x*6x = 4320
30*x*x = 4320
x*x = 144
x=12
Hence, second number = 5x = 5*12 = 60
Third number = 6x = 6*12 = 72
Ratio of first & second number = ¾
Hence, first number = ( ¾)*60 = 45
Sum of these 3 numbers = 60+72+45 = 177

Time taken to fill 2/7 = 1
Then to fill full 1 = ?
? = 1/(2/7) = 7/2 minutes.

Money invested by Rajan before 1 year was = Rs. 100000

Money in UK pounds @ 75 is = 100000/75 = 1333.33 Pounds

Now, after 1 year invested amount was appreciated by 20%

=> 20% of 1333.33 = 266.66

Total investment becomes = 1333.33 + 266.66 = 1600 Pounds

This 1600 Pounds @ Indian currency at 80 = 1600 x 80 = Rs. 1,28,000

Hence, Rajan's investment of Rs. 1,00,000 becomes Rs. 1,28,000 in 1 year

Therefore, his profit % = [(128000 - 100000)/100000] x 100 = 28%.

Amount = Rs. (30000 + 4347) = Rs. 34347.

Let the time be n years.

Then, 30000*(1+7/100)^n=34347

n= 2 years