How do you solve this question?

You would make common denominators for all of the weights. The denominator is the bottom half of a fraction. The denominators are 2, 4 and 8. The common denominator of these numbers is 8. This is because 2 times 4 is 8 and 4 times 2 is 8. Now, because you multiplied the denominator of 2 by 4, you would multiply the numerator by 4. 1 times 4 is 4. So, the first number would 2 4/8. After that you would multiply 3/8 times 2. The answer to that would be 6/8. The next number is 1 1/4. Multiply the numerator and denominator by 2, getting 1 and 2/8. Now add 2 4/8, 6/8 and 1 2/8 together. The answer is 3 and 12/8. This can also be written as 4 and 4/12, which can also be written as 4 and 1/3.
The answer is 4 and 1/3 pounds.