The answer should be 67.5gram
If Mary wants to consume 15% of her kcalories from protein, then the target calorie would be: 15% * 1800 kcal= 270kcal.
Every gram of protein will give about 4 kcal of energy. So, the protein needed in gram would be: 270kcal / (4kcal/gram)= 67.5 gram
