A woman travelled at a speed of 20 m/min for 80 min, and at a speed of 65 m/min for 64 min. Her average speed (in m/min) is:​

Correct option is A

Given:

The woman travels at a speed of 20 m/min for 80 minutes.

The woman travels at a speed of 65 m/min for 64 minutes.

Formula Used:

Average Speed = $$\frac{\text{Total Distance}}{\text{Total Time}}$$​

Solution:

$$\text{Distance}_1 = 20 \, \text{m/min} \times 80 \, \text{min} = 1600 \, \text{m}\\ \ \\\text{Distance}_2 = 65 \, \text{m/min} \times 64 \, \text{min} = 4160 \, \text{m}$$​

Total Distance = 1600 m + 4160 m = 5760 m

Total Time = 80 min + 64 min = 144 min

Average Speed = $$\frac{5760 \, \text{m}}{144 \, \text{min}} = 40 \, \text{m/min}$$​