Quantitative Aptitude - Arithmetic Ability Questions

Relative speed = (120 + 80) km/hr

=(200*5/18)m/s = (500/9)m/s

Let the length of the other train be x metres.

Then, x+270/9 = 500/9 

=>  x + 270 = 500

=>  x = 230.

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.

Number of ways of choosing 2 black pens from 5 black pens in 5C2 ways.

Number of ways of choosing 2 white pens from 3 white pens in 3C2 ways.

Number of ways of choosing 2 red pens from 4 red pens in 4C2ways.

By the Counting Principle, 2 black pens, 2 white pens, and 2 red pens can be chosen in 10 x 3 x 6 =180 ways.

As month begins on Saturday, so 2nd, 9th, 16th, 23rd, 30th days will be Sundays. While 8th and 22nd days are second Saturdays. Thus, there are 7 holidays in all.

Hence, no. of working days = 30 – 7 =23

 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%

Let the time taken by train be 't' hrs.

Then,

40t = 35t + 1560

40t = 35t + 35/4

t = 7/4 hrs

Therefore, Required length of the total journey d = s x t

= 40 x 7/4

= 70 kms.

Here S = {1,2,3,4,5,6}

Let E be the event of getting the multiple of 3

Then, E = {3,6}

P(E) = n(E)/n(S) = 2/6 = 1/3