Quantitative Aptitude - Arithmetic Ability Questions

Let S be the sample space.
Here n(S)= 23 = 8
Let E be the event of getting atmost two heads. Then,
n(E) = {(H,T,T), (T,H,T), (T,T,H), (H,H,T), (T,H,H), (H,T,H)}
Required probability = n(E)/n(S) = 6/8 = 3/4.

In two throws of a die, n(s)=(6 x 6)=36

let E= Event of geting a sum 9={(3,6),(4,5),(5,4),(6,3)}

P(E) = n(E)/n(S) = 4/36 = 1/9

circumference of A = 2πr = 8 => so r = 4π
volume = π×4π2×10 = 160π
circumference of B = 2πr   = 10 => so r = 5π
volume = π×5π2×8 =  200π
so ratio of capacities = 160/200 = 0.8
so capacity of A will be 80% of the capacity of B.

Suppose that the original price of the car = Rs. x 

Then new price of the car

=> (x) + (x ×25/100) = Rs. 5x/4 

To restore the original price, the new price must be decreased by

5x/4 − x = x/4

So required percentage =(x/4)/(5x/4) × 100%

= 20%

Given word is SCOOTY

ATQ,

Except S & Y number of letters are 4(C 2O's T)

Hence, required number of arrangements = 4!/2! x 2! = 4!

= 4 x 3 x 2

= 24 ways.

Compound Interest for 1 ¹⁄₂ years when interest is compounded yearly = Rs.(5304 - 5000)

Amount after 1¹⁄₂ years when interest is compounded half-yearly 


Compound Interest for 1 ¹⁄₂ years when interest is compounded half-yearly = Rs.(5306.04 - 5000)

Difference in the compound interests = (5306.04 - 5000) - (5304 - 5000)= 5306.04 - 5304 = Rs. 2.04

(300 – 101)/11 = 199/11 = 18 1/11

18 Numbers.

Suppose the merchant will take advantage of the cash discount of 4% of $20 000 = $800 by paying the bill within 30 days from the date of invoice. He needs to borrow $20 000 = $800 = $19 200. He would borrow this money on day 30 and repay it on day 100 (the day the original invoice is due) resulting in a 70-day loan. The interest he should be willing to pay on borrowed money should not exceed the cash discount $800.

r=I/pt=21.73%

The highest simple interest rate at which the merchant can afford to borrow money is 21.73%. This is a break-even rate. If he can borrow money, say at a rate of 15%, he should do so. He would borrow $19 200 for 70 days at 15%. Maturity value of the loan is $19 200(1+0.15(70/365))=$19 752.33

savings would be $20 000 − $19 752.33 = $247.67