Quantitative Aptitude - Arithmetic Ability Questions

let ratio be x.

Hence no. of coins be 5x ,9x , 4x respectively

Now given total amount = Rs.206

=> (.50)(5x) + (.25)(9x) + (.10)(4x) = 206

we get x = 40

=> No. of 50p coins = 200

=> No. of 25p coins = 360

=> No. of 10p coins = 160

Numbers are (2³ - 1), (3³ - 1), (4³ - 1), (5³ - 1), (6³ - 1), (7³ - 1) etc.

So, the next number is (8³ - 1) = (512 - 1) = 511.

Each of the numbers except 81 is a prime number.

We know that d=√2s 

Given diagonal = 20 cm 

=> s = 20/2 cm

Therefore, perimeter of the square is 4s = 4 x 20/2 = 402   cm.

Let A, B, C be the respective events of solving the problem and A , B, C be the respective events of not solving the problem. Then A, B, C are independent event

∴A, B, C are independent events

Now,  P(A) = 1/2 , P(B) = 1/3 and P(C)=1/4

 PA=12, PB=23, PC= 34

∴ P( none  solves the problem) = P(not A) and (not B) and (not C)  

                  = PA∩B∩C 

                  = PAPBPC         ∵ A, B, C are Independent                       

                  =  12×23×34  

                  = 14  

Hence, P(the problem will be solved) = 1 - P(none solves the problem) 

                = 1-14= 3/4

25% of 25% means

25/100 of 25/100

i.e, 1/4 of 1/4

or in other words 1/4 x 1/4=1/16

Hence, the answer is 1/16 = 0.0625.

Apply a3 + b3 + c3 - 3abca2 + b2 + c2 - ab - bc - ca = a + b + c

Hence the answer is  1.5 + 4.7 + 3.8 = 10.

Here the given series is 396, 462, 572, 427, 671, 264.

In all the terms, the middle digit is the sum of first and third digit except 427.

So the Odd number in the given series is 427.