Lemon-Limeade

Absolutely refreshing!!
5½ c water, divided
1¼ c sugar
¾ c lemon juice (4-5 lemons)
¾ c lime juice (7-8 limes)
lemon and lime slices for garnish, optional
In saucepan, heat 1½ c water and sugar until mixture boils and sugar is dissolved. Remove from heat and cool to room temperature. Meanwhile, juice lemons and limes. Combine cooled sugar water and lemon and lime juice. Chill in refrigerator for 1 hour or more. Add remaining water and serve over ice. Garnish with lemon and lime slices, if desired.