(secA – 1)/(secA + 1) is equal to?

The bus fare between two cities is increased in the ratio 17:20. Find the increase in the fare, if the original fare is Rs. 425

A missile travels at 1422 km/h. How many metres does it travel in one second?

The factors of  $$ x^2-2x-15 $$ are: 

What is total surface area of a cone where, r’ is radius and ‘l’ is slant height?   

If $$ {4x^2}={25}^2-{15}^2 $$, then find the value of x.

Divide Rs.198 in the ratio 2:3:5:8 The rupees in the respective ratios are given by: 

Given k = -3. Find the value of $$ {k^3+3k}$$.