Combine a capped geometric plan with arithmetic increments

The printed daily pattern is:

The uncapped fifth jog would exceed 400, so only days 1–4 use the GP; days 5–20 give sixteen capped jogs.

Swimming totals $\tfrac{20}2[2(200)+19(50)]=13500$ m. Jogging totals $200(1.2^4-1)/(1.2-1)+16(400)=7473.6$ m. The exact combined total is $20973.6$ m; the printed note correctly says not to round this exact value to 3 significant figures.

After day 4 the daily jog is $400$, so the daily swim must be at least $2000$ m. Solve $200+(n-1)50\ge2000$ to get $n\ge37$. The combined daily distance first reaches $2400$ m on day 37 (day 36 gives $2350$ m).