[URGENT] stuck on titration a level chemistry question

any help would be greatly appreciated to help a struggling student out haha

27.93 g of hydrated sodium carbonate Na 2 CO 3 .xH 2 O was dissolved in water and made up to 1000 cm 3 in a volumetric flask. 25.0 cm 3 of this solution required 48.80 cm 3 of 0.100 mol*dm −3 nitric acid for neutralisation.
The equation below represents the reaction between the acid and the carbonate: 2HNO 3 (aq)  Na 2 CO 3 (aq)  2NaNO 3 (aq)  H 2 O(l)  CO 2 (g)

a Calculate the amount in moles of HNO 3 needed to neutralise 25.0 cm 3 of the carbonate solution.

b Using the equation above, write down the amount in moles of Na 2 CO 3 used in the titration.

c Calculate the amount in moles of Na 2 CO 3 in 1000 cm 3 of the carbonate solution.

d Calculate the molar mass of hydrated sodium carbonate.