Decide in which of the following sentences you can use if instead of whether. 1) May I ask you whether you like classical

1) May I ask you whether/if you like classical music? 2) They were not certain of whether the task would be too hard for them. 3) Do you know whether/if this story has a happy ending? 4) The girl is still thinking whether to marry him.5) Whether the day is warm or not, we are planning to spend it outdoors.6) Ask your friend whether/if he will be able to join us for supper. 7) I still don\'t know whether or not he is planning to come. 8) We are in two minds about whether or not we should take he invitation. 9) Mark asks whether/if we are ready to begin the discussion. 10) The problem is whether or not we have visitors from abroad.