How many numbers are between 200 and 400 that begin or end with 3 explain how you got it

Removed. I made a mistake haha and someone made the correct one :)

Alright, all numbers that are in the 300 start with a 3, that's 100 numbers

hold a sec, it said 'or' not 'and', so we have to exclude those that start and end with a 3, like 303 and 313. that is 10 of them

in every hundred, there are 10 numbers that end with a 3 (the ones like 3,13,23,33,43,53,63,73,83,93)

so from 200 to 300, there are 10 of those
from 300 to 400 there are 10, wait we said 'or' so nope

100-10+10
so 100 numbers
if you are allowed to include numbers that start and end with 3 (like 303), then there are 120 numbers

Where is your question?

You have 2 sides that are 2 cms and you have 6 sides that are 1/2 cm and you have 4 sides that are 1 cm. the smallest sides are 1/2 the medium sized sides are 1 and the smallest are 1/2. so to find the perimeter you have to add them all up together so your answer will be 11 cm's