It takes 30 minutes to empty a half-full tank by draining

It takes 30 minutes to empty a half-full tank by draining it at a constant rate, It is decided to simultaneously pump water into the half-full tank while draining it. What is the rate at which water has to be pumped in so that it gets fully filled in 10 minutes?

1. 4 times the draining rate
2. 3 times the draining rate
3. 2.5 times the draining rate
4. 2 times the draining rate

Total volume = 60 S tank
(s¹ )(10) – (s)10 = 30s
s¹ (s) – s = 3s
s¹ = 4s
s¹ = 4 drawing rate