Let's take No. of large windchime be x
then no. of small windchime be 2x
now, time taken to make one large windchime is 40min and time taken to make one small windchime is 30min.
Total time is 5 hours = 300 min
so time taken to make all large chimes= 40x
time taken to make small chimes = 30*2x= 60x
total time = 300 min
40x + 60x = 300
100x = 300
x = 300/100
x = 3
total small windchimes = 2x = 2*3=6
total large windchimes = x = 3.
so I hope it's helpful. It really took some time