june 2015 planning and operational variance

i have calculated the planning and operational variance by calculating the revised standard time per unit of 1000th unit … and then calculated the planning and operational variance…
now i want to know that if there is any possibilities to assume that examiner will assume my calculation is right…because i have seen in the text book that efficiency variance can not be calculated without having a standard time per unit.

hope u will replay as soon as u can…
thank you sir….