David and Keiko walk around a track. David walks each lap in 9 minutes. Keiko walks each lap in 6 minutes. The two of them begin at the starting line at the same time. They walk until they meet again at the starting line.

they will meet at 54 minutes.

Step-by-step explanation:

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.

it would take 7/10 of an hour too fill the pool.

step-by-step explanation: