Doubt from stochiometry

In ions for calculating molar mass don't we add or subtract no of ions like in question 3 we will not add 3 for calculating molar mass of PO4 3- ?

Question no 10

10-\dfrac{ \text{molar mass}}{6×10^{23}}

For first
Multiply by number of electrons in molecule
I didnt noticed

Ok thank you

What about that ion vala doubt

Konsa?? Question number

Question 3

Question no 8 answer is 11.2 but answer key says option C is correct but i will take this as wrong how can we take 11.35 instead of 11.2