Question 1198052
Circumference of a circle = {{{pi*d}}}
each revolution advances the roller {{{pi*d}}}  0r {{{.6*pi}}}
{{{72m/(.6m*pi)}}} is the number of revolutions needed to roll 76m of lawn

IF You meant 76m^2 of lawn
THEN: n = {{{72m/(.96)(.6m*pi)}}} 
(The denominator representing a rectangular area for each revolution:
{{{ (.6m*pi)}}}x .96m )