Jeremy and Paul can plant a garden in 4 hours if try work together. If each worked alone, it would take Jeremy 6 hours longer than Paul to plant the garden. How long would it take Jeremy to plant the garden if he worked alone?

let paul alone takes = x hours

jeremy takes = x + 6 hours

work done by paul in 1 hour = 1/x

work done by paul in 4 hrs = 4/x

work done by jeremy in 1 hr = 1/(x+6)

work done by jeremy in 4 hours = 4/(x+6)

=> 4/x + 4/(x+6) = 1

=> 8x + 24 = x^2 + 6x

=> x^2 - 2x - 24 =0

=>(x+4)(x-6)=0

=> x = 6 hours

paul takes = 6 hours

jeremy takes = 12 hours