Quantitative Aptitude - Arithmetic Ability Questions

given sum =9+34+7+217-9+115

9+7+9+34+217-115

=> 7+765+120-681020=>7+8171020 

Let the Number be x. 

Given that one third of a Number is 96. 

i.e x = 3 x 96 = 288.

 67% of  x = x×67100=288×67100=192.96

A century means 100 years => 76 normal years and 24 leap years

We know that, a normal year contain 1 odd day (365/7 = 52 weeks + 1 odd day)

a leap year contain 2 odd days (365/7 = 52 weeks + 2 odd days)

100 years => 76 x 1 + 24 x 2 = 124 odd days = 124/7 = (17 weeks + 5 odd days)

200 years => 2 x 5 = 10 = 1 week + 3 odd days

300 years => 3 x 5 = 15 = 2 weeks + 1 odd day

400 years => 4 x 5 = 20 + 1 odd day (leap year) = 3 weeks + 0 odd days

500 years => 5 x 5 = 25+1 = 26/7 = 3 weeks + 5 odd days 

Again repeats...

The number of days required by a single kirlosker pump to fill the tank = 6 x 7 =42 days and the number of days required by a single USHA pump to fill the same tank = 2 x 18 =36 days.

Now , since efficiency is inversely proportional to the number of days. Hence,

Efficiency of one K - pumpEfficiency of U- pump=3642=67  

Let the leak will empty the tank in x hrs 

Then, 1/9 - 1/x = 1/13

x = 29.25 hrs

Let the actual distance travelled be x km.
Then x/8=(x+20)/12
=> 12x = 8x + 160
=> 4x = 160
=> x = 40 km.

We can initially arrange the six boys in 6! ways.
Having done this, now three are seven places and six girls to be arranged. This can be done in ⁷P₆ ways.

Hence required number of ways = 6! x ⁷P₆