He ate 25 percent of the cookies since 3 divided by 12 is .25
The block’s average speed : 0.36 m/s
<h3>Further explanation</h3>
Distance is the length traveled by an object within a certain of time .
Average speed = total distance/total amount of time ,
Can be formulated :

ΔD= total distance
Δt= total time
A block is pulled 0.90 m to the right in 2.5 s :
ΔD= total distance = 0.9 m
Δt= total time = 2.5 s
The block’s average speed :

Answer:
Elements in the same group have the same number of valence electrons.
Explanation: Science.
The substance has a higher density than water
Answer:
A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance.
Explanation:
Physical properties include color, density, hardness, and melting and boiling points. A chemical property describes the ability of a substance to undergo a specific chemical change.