Question

5/12 of my salary was spent on food, then I gave 3/7 of the remainder to my sister and had P856 left. How much did i spent for food?

Answer 1

food: 5/12, leaving 7/12

sister: 7/12 * 3/7 = 3/12, leaving 4/12 = 1/3
so, now you know that
1/3 x = 856
Find x, the whole salary.
Now you can answer the question