Answer: He is able to carry 40 letters
Step-by-step explanation: The total weight the mail carrier is allowed is 30 pounds, whereas each letter weighs 12 ounces.
What we need to do is simply find the rate of conversion between an ounce and a pound.
By conversion, 1 ounce equals 0.0625 pounds, that is;
1 ounce = 0.0625 pounds
Therefore 12 ounces would be 0.0625 times 12 which equals, 0.75 pounds. This means one letter weighs an equivalent of 0.75 pounds. If the mail carrier is allowed to carry a total of 30 pounds, then he can carry;
No of letters = Total weight allowed/weight of one letter
No of letters - 30/0.75
No of letters = 40
Hence the mail carrier is able to carry 40 letters.