Quantitative Aptitude - Arithmetic Ability Questions

Let last digit is 2
when second last digit is 4 remaining 4 digits can be filled in 120 ways, similarly second last digit is 6 remained 4 digits can be filled in 120 ways.
so for last digit = 2, total numbers=240

Similarly for 4 and 6
When last digit = 4, total no. of ways =240
and last digit = 6, total no. of ways =240
so total of 720 even numbers are possible.

Area of the sheet = 20×30cm2  

Area used for typing = 20-4×30-6cm2   

required % =384600×100=64%

P.W. = Rs. (540 - 90) = Rs. 450.

S.I. on Rs. 450 = Rs. 90.

S.I. on Rs. 540 = Rs.( 90 /450)x 540 = Rs. 108.

B.D. = Rs. 108.

Let the breadth of the given rectangle be x then length is 2x.
thus area of the given rect is 2x2

after dec 5cm from length and inc 5cm breadth , new lenght becomes 2x-5 and breadth is x+5.thus new area =(2x-5)(x+5)=2x2+5x-25

since new area is 75 units greater than original area thus
2x2+75 = 2x+5x-25
5x=75+25
5x=100
therefore x=20
hence length of the rectangle is 40 cm.

 Net growth on 1000 = (32 - 11) = 21. Net growth on 100 =(21/1000 * 100) %= 2.1%.

cost price = (225 + 15) = 240 sell price = 300
gain = (60/240)*100 = 25%

The hands of a clock coincide 11 times in every 12 hours (Since between 11 and 1, they
coincide only once, i.e., at 12 o'clock).

The hands overlap about every 65 minutes, not every 60 minutes.
The hands coincide 22 times in a day.