John traveled to his friends house and back. It took one hour longer to go there than it did to come back. The average speed on the trip there was 30km/h. The average speed on the way back was 40km/h. Hour did the trip there take?

he spend 5.1 minutes chatting with his friends.

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5.1

for this case we have that by definition, the surface area of a cylinder is given by:

where:

r: it is the radius of the cylinder

h: it is the height of the cylinder

we can also rewrite it as:

where:

la: it's the lateral area

ba: area of the base

option a