Question 105598
Since Lois travelled from home to her ftiend's house and back the distance travelled is same. Let this distance = D
Time taken on her cycle {{{t_1= D/10}}}
Time taken in the car {{{t_2= D/25}}}
Given that difference in time = 1.5 hours 
i.e. {{{ t_1 - t_2 = 1.5}}}
or {{{(D/10) - (D/25) = 1.5}}}

Can you solve for D?

Once you find D, simply divide by 10 to find how long Lois took to reach her friend's house