For this question, we can use the Combined Gas Law, which is the law and formula that perfectly correlates all 3 (volume, temperature and pressure), the formula is:
P1V1/T1 = P2V2/T2
We have:
P1 = 25 atm
V1 = 26 L
T1 = 35 K
P2 = ?
V2 = 80 L
T2 = 67 K
Now we add these values into the formula:
25 * 26/35 = P2 * 80/67
18.57 = P2*80/67
80P2 = 1244.2
P2 = 15.55 atm is the new pressure