Question 1045248
Let d = # of days of his tour programme.

===> {{{360/d - 360/(d+4) = 3}}}

<===> {{{120/d - 120/(d+4) = 1}}}

<===> 480 = d(d+4)  ===> {{{d^2 + 4d - 480 = 0}}}

<===> (d-20)(d+24) = 0  ===> d = 20, -24

Eliminating the negative candidate, the number of days in the tour programme is  {{{highlight(20)}}}.