The war party charges, each member striking at once. This final concurrency quest brings it all together: a goroutine per attacker, a channel to collect their damage, and a WaitGroup to know when every blow has landed before we tally up.
Your Quest
Inside the loop, launch a goroutine for each d that sends d into the results channel and then calls wg.Done(). Pass d in as an argument so each goroutine gets its own value.
The damages are 10, 20, and 30, so:
60
Hint
go func(d int) { results <- d; wg.Done() }(d) — passing d as a parameter gives each goroutine its own copy.