Danny has 3 bottles of soda. He drinks 90% of one bottle and gives 70% of the other two bottles to his friends. How much soda does Danny have left, expressed as a percentage of a bottle?
Think hard. Detailed solution:
70
First find how much soda Danny drank: 1 bottle *.

9 =.

9 bottles.

Then find how much soda Danny gave to his friends: 2 friends * 1 bottle / friend *.

7 = 1.

4 bottles.

Now subtract the soda drunk and given away to find the remaining amount of soda: 3 bottles -.

9 bottles - 1.

4 bottles =.

7 bottles * 100% = 70%.

.

The final answer: 70