Quantitative Aptitude - Arithmetic Ability Questions

Given speed of the first train = 60 km/hr = 60 x 5/18 = 50/3 m/s

Let the speed of the second train = x m/s

Then, the difference in the speed is given by

503 - x = 12018

=> x = 10 m/s

=> 10 x 18/5 = 36 km/hr

x = 90% of y = 

=> y = 1.1% of x.

Sum of the decimal places = 7 .

Since  the last digit to the extreme right  wil be zero ( 5 * 4 = 20),  so there will be  6  significant digits to the right of the decimal point....

Let average for 10 innings be x. Then,

(10x + 108)/11 = x + 6 => 11x + 66 = 10x + 108  =>  x = 42.

New average = (x + 6) = 48 runs.

Maneela lent Rs. 8000 in two parts,

Let us assume Amount be 100 Rs and we calculate in CI

 First year 60% of 100 = 60 amount (100+60) is 160

 Second year 60% of 160 = 96 amount (160+96) is 256

 Third year 60% of 256 =153.6 amount (256+153.6) is 409.6

 Here the Amount of 100 Rs is quadrapled in 3 years.

 One year contains 2 half years

 Three year has 6 half years.

 Therefore,  It takes 6 half years.

Let the two no's be a and b;
Given product of the no's is p = ab;
If the each nos is increased by 2 then the new product will be
(a+2)(b+2) = ab + 2a + 2b + 4
= ab + 2(a+b) + 4
= p + 2(a+b) + 4
Hence the new product is (p+4) times greater than twice the sum of the two original numbers.