🏊 Catch-Up in the Lane

Two swimmers, one lane, ten seconds apart. Turn the head start into yards, close the gap at a rate, and write the catch as an equation.

Two swimmers, one lane

Swimmer B leaves first and holds 1:30 for every 100 yards. Ten seconds later Swimmer A leaves and holds 1:20. A is faster, so A will catch B. The question is where.