Translate into Russian. Pay attention to the translation of the conjunction

Translate into Russian. Pay attention to the translation of the conjunction if when it introduces object clauses: 1) If you want me to help you, why don39;t you say so? 2) I don39;t know if there are any Bulgarians in the delegation. 3) Let39;s meet at nine o39;clock if it is convenient for you. 4) Tell me if I may take these books home. 5) I don39;t know if it is so. 6) Why not go now if you want to see the illumination? 7) Ask him if he often comes home so late. 8) Would you like to join us if we go to Red Square? 9) I wonder it he likes his job. 10) Ask him if he has got any pen-friends in India.