Question about a floral arrangement of tulips that I made!!?

Question:Hi! I'm very inexperienced in making floral arrangements, but I did one today for the first time (for Mother's Day). Anyway, it's of tulips (all tulips, as that's the only flower she's not allergic to), and I pulled off some of the leaves that were all cruddy and brown. Will that make the flowers die more quickly? I figured that the leaves were already dead, so taking them off wouldn't hurt. Not to mention, it looked horrible with the dead leaves. I also cut the flowers at an angle and put them in a vase. What I'm wondering is, what temperature of water do I put in? Do you put hot water (like a Christmas tree) or cold? Is there anything I should put in the water to make them last longer? Thank you sooooooo much! Immediate help is appreciated because she'll be home in like a half-hour. THANK YOU!

Answers:
Removing dead leaves should benefit the arrangement rather than hurting it. Cutting at an angle is good as well. I believe lukewarm water with half a teaspoon of sugar will help prolong the life of the flowers.