Answer: The family uses 3 Gb in the entire month.
Explanation:
A month has 30 days.
If in 10 days the family uses 1Gb, then in each day the family uses:
R = 1Gb/10 days = 0.1 Gb per day.
Then in 30 days the family uses:
30days*0.1 Gb er day = 3 Gb
The family uses 3 Gb in the entire month.