Quantitative Aptitude - Arithmetic Ability Questions

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...

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

By investing Rs. 136, income obtained = Rs. 10.

By investing Rs. 6800, income obtained = Rs.1036×6800 = Rs. 500.

Let the ten's digit be x and unit's digit be y. Then, (10x + y) - (x + y) = 9 or x = 1.

From this data we cannot find  y, the unit's digit. So the data is inadequate..

Shopkeeper sells at CP using weight of 900 gm instead of1 kg

So, 1000gm –900 gm = 100gm

⇒100/900 X 100

⇒100/9 %

Cost of each cake P1 & P2 = Rs. 12

Offer decrease in % = 20%

Increase in sale per day (Q2) = 250 - 18%

Total quantity per day (Q1) = 250

Hence, required change total revenue

TR = P2Q2 - P1Q1 = (12 x 0.8 x 250 x 1.18) -  (12 x 250) = - Rs.168.

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