Quantitative Aptitude - Arithmetic Ability Questions

n items of which p are alike of one kind, q alike of the other, r alike of another kind and the remaining are distinct can be arranged in a row in n!/p!q!r! ways.
The letter pattern 'MESMERISE' consists of 10 letters of which there are 2M's, 3E's, 2S's and 1I and 1R.
Number of arrangements = 9!(2!)2×3!

$$\begin{gathered} 6760000=0.00000676×102 \\ = 0.00000676 ×102 \\ = 0.0026×106 = 2600 \end{gathered}$$

Let the total work be 'W'

As per the given information,

P can complete the work 'W' in 24 days.

=> one day work of P = W/24

And also given that,

The time taken by P to complete one-third of work is equal to time taken by Q to complete half of the work

=> PW/3 = QW/2

=> P's

1 day =    W/24

   ?    =      W/3

=>  ?  = 24W/3W  = 8

=> QW/2 = 8 days

=> Q alone can complete the work W in 16 days

=> P + Q can complete the work in

1/24 + 1/16 = 5/48

=> 48/5 days = 9 3/5 days.

Let the total capacity of tank be 90 liters.
Capacity of tank filled in 1 minute by K = 3 liters.
Capacity of tank filled in 1 minute by L = 15 liters.
Therefore, capacity of the tank filled by both K and L in 1 minute = 18 liters.
Hence, time taken by both the pipes to overflow the tank = 90/18 = 5 minutes.

Given ratio = 1/2:2/3:3/4 = 6:8:9

1st part = 782 x 6/23 = Rs. 204.

Part filled in 4 minutes = 4(1/15 + 1/20) = 7/15

Remaining part = 1 - 7/15 = 8/15

Part filled by B in 1 minute = 1/20

1/20 : 8/15 :: 1 : k

k = (8/15 )x 1 x 20 = 10( 2/3) min = 10 min 40 sec.

The tank will be full in (4 min. + 10 min. 40 sec) = 14 min 40 sec.

Let Hari Ram's present age = x

Then, his son's age = x/3

Father's age = 5x/2

$$\begin{gathered} x + x3 + 52x3 = 46 \\ => x = 36 yrs \end{gathered}$$

Now the required difference = 52x36 - 363 = 78 yrs

Let the list price be Rs.100. 

Therefore, the retailer is buying the products at Rs.60 and selling it to the customer at Rs.75, earning a profit of Rs.15.

Therefore, his percentage is = 1560x100 = 25%