Answer:
270 people
Step-by-step explanation:
If we think of the ratio as "parts", it becomes very easy!
In total there are 3 + 7 = 10 parts
Really, in the town there are 900 people so each part is [tex]\frac{900}{10}=90[/tex] people
And we know 3 parts get their news from Frontbook, so 3 parts is [tex]90*3=270[/tex] people