Quantitative Aptitude - Arithmetic Ability Questions

= 4 : 2 = 2 : 1

Thus, the two varieties should be mixed in the ratio 2 : 1

Let a and b are the numbers.Then a+b is 12 and ab is 35.

a+b/ab = 12/35

1/b + 1/a = 12/35

The number of exhaustive outcomes is 36.
Let E be the event of getting an even number on one die and an odd number on the other. Let the event of getting either both even or both odd then = 18/36 = 1/2
P(E) = 1 - 1/2 = 1/2.

Frequency of step of A:B:C = 5 : 6 : 7

But in terms of size of step, 6A = 7B = 8C

Therefore, Ratio of speeds of A, B and C = 5/6 : 6/7 : 7/8 = 140 : 144 : 147

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.

let the radius of the pool be Rft

Radius of the pool including the wall = (R+4)ft

Area of the concrete wall = πR+42-R2=πR+4+RR+4-R = 8πR+2 sq feet

=> 8πR+2 = 1125πR2 =>11R2 =200R+2

Radius of the pool R = 20ft

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