Answer:
3.) 3:7
Explanation:
We know
Of the 300 television sets sold at an electronics store last month, 90 were flat-screen TVs.
300 - 90 = 210
So, we know the store sold 90 flat-screen TVs and 210 other TVs
What was the ratio of flat-screen TVs to other TVs sold last month?
The ratio is
90:210
3:7
So, the answer is 3.) 3:7