Can you help me with this problem. If you can explain it to me i'll be thankfull.

If the radius of the balloon is doubled, then it means that the volume of the balloon will go up by a factor of: 2^3=8 times the volume of the smaller balloon. 

im sorry bu there is no image i cant help you if there is no image sorry

Volume of a sphere = 4/3 pi r^3    Now lets make r=2r  (doubling the radius of the baloon

     volume = 4/3 pi (2r)^3 = 4/3 pi 8 r^3

Now the second volume to the original volume ===   (4/3 pi 8 r^3)  / (4/3 pi r^3) = 8/1 = 8 times more volume!