Question 266027
The first mower can mow {{{1/7}}} of the yard in 1 hour.
The second mower can mow {{{1/6}}} of the yard in 1 hour.
Together, they can mow {{{1/7 + 1/6 = 13/42}}} of the yard in 1 hour.
So it would take them {{{42/13}}} hours to mow the entire yard.
{{{42/13 = 3.2307}}} hours.  
Rounded to the nearest tenth this would be 3.2 hours.