Jeffery biked to the store at 12 miles an hour but took his time on the way home, going 8 miles an hour if it took him 20 minutes to get to the store, how many minutes did it take him to get back?

It takes 30 minutes to get back

Step-by-step explanation:

Jeffery biked to the store at 12 miles per hour. This is the speed at which he biked on his way to the store. He covered this distance to the store in 20 minutes.

Converting 20 minutes to hours, we divide by 60.

20 minutes =20/60 hours

Distance which Jeffrey covers on his way to the store at a speed of 12 miles/ hour and time of 20/60 hours is

Speed = distance / time

Distance = speed × time = 12× 20/60

= 4 miles.

The distance remains the same on his way back even though his speed reduced to 8 miles/ hour

Time taken to get back = distance/ speed

= 4 /8 = 0.5 hours

Converting to minutes

0.5 × 60 = 30minutes

you need a common difference between consecutive terms to be constant, like 1,2,3,4 or 2,4,6,8, or 1,3,6,9