Question

Jack and Jones are on a relay race. Jack runs at a speed of 12 km/h and Jones runs at 10 km/h.

a) \( D = 12x + 10y \)
b) \( D = 22xy \)
c) \( D = 12x \times 10y \)
d) \( D = 22(x + y) \)

Answer 1

The correct equation to represent the total distance covered by Jack and Jones in a relay race is option a) D = 12x + 10y, where x and y are the times in hours that Jack and Jones run, respectively.

Step-by-step explanation:

The question involves determining the correct equation to represent the total distance covered by Jack and Jones in a relay race, given their running speeds. In a relay race, one runs after the other, contributing their distance sequentially. So, it is not a simultaneous action where each participant contributes distance at the same time which would be the case in option b), c) and d). Therefore, option a) D = 12x + 10y is the correct equation, where x and y represent the time in hours that Jack and Jones run, respectively. With Jack running at a speed of 12 km/h, he covers 12 km for every hour he runs (12x). Similarly, Jones running at a speed of 10 km/h, covers 10 km for every hour he runs (10y). To find the total distance D that both have covered, we add these distances together.