Arigid tank having a volume of 0.100 m3 contains helium gas at 150 atm. how many balloons can be inflated by opening the valve at the top of the tank? each filled balloon is a sphere 0.300 m in diameter at an absolute pressure of 1.20 atm

The initial value of P*V = 0.100*150 atm-m³ 
 Each balloon has a volume of (4/3)*π*r³ and N balloons have a volume of N*(4/3)*π*r³ 
 When all the balloons are inflated, the pressure in the tank is the same as the pressure in the balloons, so the final value of P*V is 
 1.20*[N*(4/3)*π*r³ + 0.100] 
 0.100*150 = 1.20*[N*(4/3)*π*r³ + 0.100] solve for N: 
 15/1.2 = N*(4/3)*π*r³ + 0.100
 12.5 - 0.100 = N*(4/3)*π*0.150³ 
 12.4 = N*0.01414 
 N = 877