Given that ,
Order of the B tree = 199
it means in each block we have = 198 index record
At root no of index record = 198
At 2nd level no of index record = 198 * 199
At 3rd level no of index record = 198 * (199)3-1
similarly at level "h" no of index record = 198*(199)h-1
therefore,
$\sum_{level=1}^{h}$ (198)*(199)h-1 = 69,99,996
198 [ (199)0 + (199)1 + (199)2.......(199)h-1] = 69,99,996
198 * ((199)h -1 / (199-1)) = 69,99,996
199h-1 = 69,99,996
199h = 6999997
h = 2.977
h = 3