[tex]\text {Kylie =} \dfrac{1}{4} \text { cup}[/tex]
[tex]\text {Sister =} \dfrac{1}{4} \text { cup}[/tex]
To find how much do they have in all, we add them:
[tex] \dfrac{1}{4} + \dfrac{1}{4} = \dfrac{2}{4} [/tex]
Then we try to reduce the fraction to the simplest possible:
[tex] \dfrac{2}{4} = \dfrac{2\div 2}{4 \div 2} = \dfrac{1}{2} [/tex]
[tex]\text {Answer= } \dfrac{1}{2} [/tex]