Answer:
270 people
Explanation:
If we think of the ratio as "parts", it becomes very easy!
- 3 parts get their news from Frontbook
- 7 parts get their news from elsewhere
In total there are 3 + 7 = 10 parts
Really, in the town there are 900 people so each part is
people
And we know 3 parts get their news from Frontbook, so 3 parts is
people