exam Maths Puzzle Numerical Ability

please help me solve this problem in quadratic equation;
1.a motorboat takes 4 hours to travel 30 miles downstream and then 18 miles upstream on a river whose current flows at the rate of 3 miles per hour. How fast can the boat travel in still water?

Read Solution (Total 0)

exam Other Question
if I have the height and volume of a cylinder, how do I find the radius? or diameter? Let f(x) =2x+5 and g(x) = x^2+4 Find the following:

(g*f)(x)
f(g(x))
(f*g))(-3)
g(f(4))

These are compositions of functions, not multiplication.