0.5 hour - 40mph = 20miles
0.25 hour - 0mph = 0 miles
x hour - 60mph
x = 1hour - 0.5 -0.25 = 0.25hour

0.25 hour 60mph = 15miles

total mile = 20+15 = 35miles in 1 hour

so 35 miles per hour

have to write out how u arrive to the answer. if just tembak 35, only 1 markah
if write out the steps, you get additional 99 markah