First thing, you convert from kPa to Pa. Then, you find the atm value of the Pa you got.
155 kPa = 155 000 Pa
1 atm = 101 325 Pa
x atm = 155 000 Pa
You divide 101 325 over 155 000 and you get about 1.53
So, 155 000 Pa = 1.53 atm.
So, T (temperature) = 25 + 273 = 298
605 kPa = 605 000 Pa
1 atm = 101 325 Pa
x atm = 605 000 Pa
You divide 605 000 over 101 325 and you get about 5.97
So 605 000 Pa = 5.97 atm
So, T = 125 + 273 = 398
P1 V1/T1 = P2 V2/T2
1.53 1/298 = 5.97 V2/398
You calculate ad you get V2 = 0.342 L
Hope this Helps :)