If we consider the following: 15000 feet indicated at QNH 1030 and standard atmos temperature of -15°C
If we consider a "standard" descent speed of 290 IAS we get a TAS of 365 Kts. 30 Kts Headwind means 335 Kts Groundspeed.
(used http://indoavis.co.id/main/tas.html )
How many minutes for 24 miles to calculate: (24 miles / 335 Kts) * 60 = 4,298 Minutes
so to go from 15000 feet to 3000 feet we need to decent 12000 feet in ~ 4,3 Minutes = 2790 feet/minute decent rate. The Question is, if the Airbus is capable of this rate below FL 100
according to https://www.skybrary.aero/index.php/A320
until FL100 a decentrate of 3500ft/min is possible with 290 Kts IAS, but I do not have any info found on the sharklet version oder belo FL100