In the following program, for example, `r`

's value is `5.0`

before `doubling_time`

has been entered, `r`

's value
is `10.0`

as `doubling_time`

is executed, and `r`

's value
is `5.0`

after the execution of `doubling_time`

.

#include#include /* Define doubling_time first */ double doubling_time (double r) { return log (2.0) / log (1.0 + r / 100.0); } /* Then, define main */ main ( ) { double r = 5.0; printf ("The value of r is %f.\n", r); printf ("The doubling time at twice that rate is %f.\n", doubling_time (r + r)); printf ("The value of r is still %f.\n", r); } --- Result --- The value of r is 5.000000. The doubling time at twice that rate is 7.272541. The value of r is still 5.000000.