We are given that Donna knit a total of 12 blankets.
She took 4 months in doing it.
To find the number of blankets in 1 month, take ratio of number of blankets to number of months.
[tex] \frac{number \: of \: blnkets}{number \: of \: months} \\ \\ = \frac{12 \: blankets}{4 \: months} \\ \\ = \frac{3 \: blankets}{1 \: months} [/tex]
Thus, she knit 3 blankets in 1 months