Answer:
15 quarts
Step-by-step explanation:
Given,
The garden house emits 9 quarts of water in 6 seconds,
That is, the time required for emitting 9 quarts of water = 6 seconds,
∴ The ratio of emitted water and time =
= 
Let x be the emitted water ( in quarts ) in 10 seconds,
So, the ratio of emitted water and time = 



Hence, 15 quarts of water emitted in 10 seconds.