HEYOO PEEPS 1. Ethan Rides his bike up a 20km hill in 2hrs. Ethan rides his bike down the 20km hill in .5 hrs. What is Ethan’s average speed?

let Leo's speed = x mile/hr

so Ethan speed = (x + 6) miles per hour

Distance = Speed × Time

so distance traveled by Leo in 2 hours = x × 2 = 2x

and distance traveled by Ethan in 1.5 hours = 1.5( x + 6 ) = 1.5x + 9

since  they meet on the path , After Ethan has ridden 1.5 hours and Leo has ridden 2 hours , so together the have traveled on complete path that is 65 miles.

⇒  distance traveled by leo in 2 hours + distance traveled by Ethan in 1.5 hours = 65

⇒  2x + 1.5x + 9 = 65

⇒ 3.5x = 56

⇒ x = 16

Hence Leo's speed = x miles/hr = 16 miles/hour

and Ethan's speed = (x + 6) miles/hr = 16 +6 = 22 mile/hour

Explanation:

sorry if this isnt the one im think of

a chemical reaction happens

explanation:

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.