Or an easier to remember formula for question 1
+/- 4' per degree of ISA Devn x (ht/1000)
Where ht = the height above the temperature datum, which is the airfield.
+4x15(7.5)
So at an indicated altitude of 10000' your altimter will be overeading by 450' giving a true altitude of 9550'.
Q2 is simply at a matter of 'winding' your altimeter up to 1013 to get pressure alt. 13Hp x 30' per Hp = +390' hence B.
Chuckles.
PS but I do like the TA formula with degrees Kelvin, being a naturally enquisitive bloke so I'll write it down and attempt to memorise it
