A certain sum amounts to $2200 in 2 years to $2800 in 4 years at simple interest. Find the sum and the rate per cent per annum.

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads

answer: i think you should do the math and pay attention in class : )

step-by-step explanation:

that is truly what   think but if i get the answer i will

what is the your question?