James hurt himself exercising.  The pain subsided after 3 days, but he knew that the injury would take at least 5 times that long to fully heal. After that, he wanted to wait another 3 days before he started working out again.  If he wants to wait 3 weeks after that to start lifting heavy again, how long until he can lift heavy again?
The injury would be fully healed after 3*5=<<3*5=15>>15 days
So he would start exercising again in 15+3=<<15+3=18>>18 days
He would then wait for 3*7=<<3*7=21>>21 more days to start lifting heavy again
That means he needs to wait 18+21=<<18+21=39>>39 days
#### 39