Answer
(a) Average speed of insect is $0.027\,\mathrm{m/s}$.
(b) Magnitude of average velocity of insect is $0.019\,\mathrm{m/s}$.
Work Step by Step
(a) Distance traveled by the insect, $x=27+21=48\,\mathrm{m}$.
Time taken, $t=30\times 60=1800\,\mathrm{s}$.
Average speed, $s=\frac{x}{t}=\frac{48}{1800}=0.027\,\mathrm{m/s}$.
(b) Displacement of the insect, $d=\sqrt{27^2+21^2}=34.2\,\mathrm{m}$.
Magnitude of average velocity, $v=\frac{d}{t}=\frac{34.2}{1800}=0.019\,\mathrm{m/s}$.