The tourist walked for the first 15 minutes at a speed of 6 km / h and then for 45 minutes

The tourist walked for the first 15 minutes at a speed of 6 km / h and then for 45 minutes walked at a speed of 4 km / h. Determine the average speed of the tourist along the entire route.

To calculate the value of the average speed of the tourist under consideration, we apply the formula: Vav = S / t = (Sn + Sk) / (tn + tk) = (Vn * tn + Vk * tk) / (tn + tk).

Variable values: Vн – initial speed (Vн = 6 km / h); tн – the first time (tн = 15 min = 0.25 h); Vк – the final speed of the tourist (Vк = 4 km / h); tk – the second time (tk = 45 min = 0.75 h).

Calculation: Vav = (Vn * tn + Vk * tk) / (tn + tk) = (6 * 0.25 + 4 * 0.75) / (0.25 + 0.75) = 4.5 / 1 = 4.5 km / h.

Answer: The average speed of the tourist in question was 4.5 km / h.

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