I walk to the bike shop at 3 miles per hour and cycle back along the same route at 12 miles per hour. What is my average speed, in miles per hour, for the time I am actually travelling on the route?

7.5 miles per hour

Step-by-step explanation:

First speed was 3 miles per hour.

Second speed was 12 miles per hour.

To do an average, add both speeds and divide by two, which is the number of trips made.

= (3 + 12) / 2

= 15 / 2

= 7.5 miles per hour

LXVII

Step-by-step explanation:

The roman numeral for 67 is LXVII

LX represents 60 and VII represents 7