Answer:
$1200
Explanation:
Given that:
Monthly subscription fee = $10
Last month's subscribers = 100
THIS MONTH:
New subscribers = 30
canceled subscriptions = 10
Hence,
Total number of subscribers this month :
(Last month subscription + new subscriptions - canceled subscriptions)
(100 + 30 - 10) = 120 subscriptions this month
Hence, amount earned this month will be :
(Total subscriptions this month * monthly subscription fee)
120 * $10 = $1200