Need some help with Boolean Logic 2

Question

Hello!
Could someone tell me what's wrong with this code exactly?

purity = float(input())
#your code goes here

if purity >= 75.0 and purity < 83.3:
print ("18K")
if purity >= 83.3 and purity < 91.7:
print ("20K")
if purity >= 91.7 and purity < 99.9:
print ("21K")
if purity > 99.9:
print ("24K")

It works for the first 3 cases, also for the cases 4 and 7 from the hidden ones, but it marks as invalid for the cases 5 and 6, and i can't notice why since they're locked

Answer 1

purity = float(input())
if 75.0 <= purity < 83.3:
print ('18K')
elif 83.3 <= purity < 91.7:
print ('20K')
elif 91.7 <= purity < 99.9:
print ('22K')
else:
print ('24K')

Check this one now.

This works.

Answer 2

Can you post your question? RogerRM