What is 221,000,000,000,000,000,000 expressed in scientific notation? a.2.21 × 1021 b.2.21e20 c.2.21e21 d.2.21e-20 e.2.21 × 10-21 f.2.21 × 10-20 g.2.21 × 1020 h.2.21e-21

221,000,000,000,000,000,000 = 2.21 x 10^20

therefore, the answer is b

Step-by-step explanation:

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