Aptitude and Reasoning Questions

Distance covered by A till 6pm = 60 km

Distance covered by A till 7 pm = 120 km

Time taken by B to catch A = 60/(80-60 ) = 3 hrs

So A and B will meet at 6pm + 3 hrs = 9pm

Since we know that all three met at the same time

The time taken by C to cover 120 km

difference will be  = 9pm –7pm = 2hrs

Therefore,(x –60 )*2 = 120x = 120 km/hr

False. Cube is not a Polygon.

Because polygon is a two dimensional figure and can be drawn on a flat surface whereas Cube is three dimensional figure and cannot be drawn on a flat surface.

Divisibility rule for 24 is the number should be divisible by 3 and 8. As we know that 24 = 3 x 8

Now, 

Divisibility rule for 3 :

If the sum of the digits of a number is divisible by 3, then the number is divisible by 3.

Divisibility rule for 8 :

The last three digits of a number should be divisible by 8.

Hence, check for the given options,

A) 37804 => 804 is not divible by 8.

C) 36718 => 718 is not divible by 8.

D) 53810 => 810 is not divible by 8.

B) 2015736 => 736 is divisble by 8 and sum 2 + 0 + 1 + 5 + 7 + 3 + 6 = 24 which is divisible by 3.

Hence, 2015736 is divisible by 24.

Let avg ages of 5 members at present is G

And age of new member is m and an older is n

Required = (5G + m - n)/5 = G - 3

m - n = 15 years

(3x + 2) (2x - 5) = ax2+kx+n ...............(1)

But (3x + 2)(2x - 5) = 6x2-11x-10........(2)

so by comparing (1) & (2),

we get a= 6, k= -11 , n= -10

(a - n + k) = 6 + 10 - 11 = 5.