Final answer:
Tina will need to use 3/8 cup of sugar.
Step-by-step explanation:
Tina is making sweet tea and usually uses 1/2 cup of sugar. She wants to increase the amount of sugar in her tea by 75%. To find how much sugar she will need, we can first calculate 75% of 1/2 cup.
75% of 1/2 cup = (75/100) x (1/2) cup = (3/4) x (1/2) cup = 3/8 cup
Therefore, Tina will need to use 3/8 cup of sugar.