Mathematics for IGCSE & O level - Rates (Section 2 - No. 23)
A runner's average speed in an 80 m race is 7 m/s. Find the time she takes for the race, to the nearest 0.1 second.
9.5 s
10.3 s
11.4 s
12.1 s
คำอธิบาย
Time = Distance / Speed. Time = 80 m / 7 m/s = 11.4 s