Mila Sofa

A petrol station finds that its daily sales, in litres, are normally distributed with mean 4520 and standard deviation 560. (a) Find on how many days of the year (365 days) the daily sales can be expected to exceed 3900 litres.

A train is going at 1/3 of its usual speed and it takes an extra 30 minutes to reach its destination. Find its usual time to cover the same distance.

I wasn't given the distance, but isn't there any way to solve it?

its A