Agas is contained in a thick walled balloon. when the pressure changes from 100 kpa to 90.0 kpa, the volume changes from 2.50 l to 3.75 l and the temperature changes from 303 k to k

Let's assume the gas is acting ideally, Then, applying Ideal Gas Equation, assuming number of moles constant,

                                   P₁ V₁ / T₁  =  P₂ V₂ / T₂      (1)
Data:
         P₁  =  100 kPa
 
         P₂  =  90 kPa

         V₁  =  2.50 L

         V₂  =  3.75 L

         T₁  =  303 K

         T₂  =  ?

Solving Eq. 1 for T₂,

                                 T₂  =  (P₂ × V₂ × T₁) × (P₁ × V₁)
Putting Values,
                                 T₂  =  (90 kPa × 3.75 L × 303 K) ÷ (100 kPa × 2.50 L)

                                 T₂  =  409 K