Maisie needs 25/4 or 6 1/4 pounds of candy for her piñata.
1) Gathering the data from the question:
Masie needs 12 1/2 pounds of candy
She already has 3/4
Her mother gave her : 5 /12
2) Let's turn those mixed numbers into improper fractions first:
2.1) Keep the denominator, multiplying it an adding it to the numerator
12 1/2 = 25/2
5 1/2 = 11/2
3) She needs then 25/2 how many more, let's call it x
11/2 +3/4 +x = 25/2 Factoring the denominators
(2*11 +1*3)/4 +x = 25/2
25/4 +x = 25/2
25/4-25/4 +x= 25/2 -25/4
x = 25/4 or x = 6 1/4
