working out mark up on cost

JJY

I have an accounts for sole traders and partnerships exam soon and I'm really stuck on one question

it asks ": Calculate the COGS for year ended xxx

total sales where 66,000
total purchases where 59,120
a mark up of 20% on cost was used throughout the year

i dont understand the formula for this

it then asks calculate the value of the inventory for the year as at xxx

again i don't know how to work that out either

any help would be much appreciated

JJY

actually ignore this I've just answered my own question ha !