Answer
$5\times 10^{9}$ floating-point operations
Work Step by Step
Number of characters in one page = 65*60 = 3900
Time taken by printer = 3900/780 = 5 seconds
1 gigaflop machine will perform $10^{9}$ floating-point operations in 1 second.
Hence, in 5 seconds it will perform $5*10^{9}$ floating-point operations.
