Question 391655
time = distance/speed
so, if we find the distance each swimmer covers, we can get the time they meet
let x = distance covered by first swimmer
1-x = distance covered by other swimmer
there is only one time involved, the time both swimmers meet
x/4 = (1-x)/5
4-4x =5x
9x =4
x=4/9 mi (distance covered by first swimmer
1-x = 5/9 mi (distance covered by second swimmer

time swimmers meet = (4/9)/4 =1/9hr or (5/9)/5 =1/9 hr

ans: swimmers meet in 1/9 hr or 6-2/3 minutes