Answer:
150 oz.
Step-by-step explanation:
There are already 150 ounces of alloy of nickel.
Of this 150 oz, 70% is pure i.e. nickel content = 150(0.7) = 105 oz
Now available is
Nickel Other metals
105 45
Let x oz of pure nickel is added.
Then new alloy will have 105+x oz nickel in total of 150+x oz.
Percentage pure = 
Simplify to get

Hence answer is 150 oz should be added.
Answer:
: The percentage of newborn infants who are exclusively breastfed at the time of hospital discharge.
Data Source: Rhode Island Department of Health, Center for Health and Data Analysis, Newborn Developmental Risk Screening Program Database and Maternal and Child Health Database.
Footnotes: The year indicated is the mid-year of a five-year period of data.
Step-by-step explanation: