Question

A person, who decided to go to weekend trip should not exceed 8 hours driving in a day. Average speed of forward journey is 60 km/h. Due to traffic in Sundays, the return journey average speed is 50 km/h. How far can he select a picnic spot?

Answer 1

Since he must not exceed 8 hours driving in a day:
Let the distance of the picnic be = x km.

Therefore  time for forward journey  =  x / 60
Return journey                                   =  x / 50

The total trip should not exceed 8 hours.
Therefore:              x / 60 + x / 50  <= 8.      LCM = 300

Taking LCM and multiplying on both sides:
                                5x  +  6x  <=  8(300)
                                       11x    <=  2400
                                           x    <=    2400/11
                                           x   <=  218.18
The picnic spot must be less than or equal to 218.18 km.