Quantitative Aptitude - Arithmetic Ability Questions

Let the present ages of Ajay and Vijay be 'A' and 'V' years respectively.

=> A - 8 = 4/3 (V - 8) and A + 8 = 6/5 (V + 8)

=> 3/4(A - 8) = V - 8 and 5/6(A + 8) = V + 8

V = 3/4 (A - 8) + 8 = 5/6 (A + 8) - 8

=> 3/4 A - 6 + 8 = 5/6 A + 20/3 - 8

=> 10 - 20/3 = 10/12 A - 9/12 A

=> 10/3 = A/12 => A = 40.

Side of smallest cube = L.C.M of 5, 10, 20 = 20cm  

Volume of the cube = (20 x 20 x 20)cu.cm = 8000 cu.cm  

Volume of the block= (5 x 10 x 20)cu.cm = 1000 cu.cm  

Number of blocks = (8000/1000) = 8

Amount of milk left after 3 operations

401-4403=40*910*910*910=29.16 litres

ratio = 1/2×2d212d2=4:1

The first lost Rs. 100, but after the thief bought Rs. 60 goods, he get that Rs. 100 back but he lost Rs. 60 value of goods and Rs. 40 in change.

So, a total of 60 + 40 = 100 Rs. the owner lose.

Find the number of cases in which none of the digits show a '6'.

i.e. all three dice show a number other than '6', 5×5×5=125 cases.

Total possible outcomes when three dice are thrown = 216.

The number of outcomes in which at least one die shows a '6' = Total possible outcomes when three dice are thrown - Number of outcomes in which none of them show '6'.

=216−125=91

The required probability = 91/256

Let the mother's present age be x years.

Then, the person's present age = 2/5 x years.

(2x/5 + 8) = 1/2 (x + 8)

2(2x + 40) = 5(x + 8) => x = 40.

Excluded number = (27 x 5)  -  (25 x 4) = 135 - 100 = 35.