Answer:
She has 5 candles left.
Explanation:
Total of candy Sarah has = 25candies
If Sarah gave 2/5 of the candies to her sister, the total amount she gave her sister will be 2/5 of 25
2/5 of 25 = 10
The remaining candy left will be 25-10 which is 15.
If she gave 2/3 of the amount left to her friend, the amount she gave her friend will be 2/3×15 = 10candies.