Quantitative Aptitude - Arithmetic Ability Questions

Let there are L men

job requires LK man hours.

job completed in first 4 hrs = L x 4 = 4L

job completed in next 4 hrs = 4 x L/2 = 2L

job completed in next 4 hrs = 4 x L/4 = L

job completed in last 4 hrs = 4 x L/8 = L/2

4L + 2L + L + L/2 = KL

K = 7+1/2 = 7.5 hours.

Since it does not matter what order the committee members are chosen in, the combination formula is used.

Committees are always a combination unless the problem states that someone like a president has higher hierarchy over another person. If the committee is ordered, then it is a permutation.

C(17,7)= 19,448

Let Rajan's present age be 'x' years.
=> Then his daughter's present age is = x/3 years.
His mother's present age = 13x/9 years
Now, according to the question,
x + x/3 + 13x/9 = 125
=> x = 125x9/25 = 45
Therefore, required difference = 13x/9 - x/3 = 13x - 3x/9 = 10x/9
=> 10 x 45/9 = 50 years.

Ratio of investments for 1 year

=> (P : Q : R) = (2x2 + 2.4x10) : (3x2 + 3.3x10) : (5x12)

=> (P : Q : R) = 28 : 39 : 60

Now R share = 190500 x 60/127 = Rs. 90000.

Let the cost price of the item = Rs. 50

Sold at 10% loss => for Rs. 50 loss  S.P = Rs. 45

From the  given data,

25/2 % gain if it is sold at Rs. 9 more

56.25 - 45 = 9

=> 11.25 = 9

=> 22.5 = 18

=> 45 = 36

=> 50 = ?

=> C.P = 50 x 3645 = 40

Hence, the Cost price of the item = Rs. 40.

The year 1985 is an ordinary year. So, it has 1 odd day.

So, the day on 19th June, 1985 will be 1 day after the day on 19th June, 1984.

But, 19th June,1984 is Monday

S0, 19th June, 1985 is Tuesday.

Let x liter be the per day filling and v litr be the capacity of the reservoir, then 

      90x + v = 40000 * 90     -----(1)

      60x + v= 32000 * 60     ------(2)

solving eq.(1) and (2) , we get

      x = 56000

Hence , 56000 liters per day can be used without the failure of supply.