Annie goes to school. Today is her birthday, so Annie decided to buy some sweets for her colleagues. Every classmate got 2 candies. In the end, Annie got left with 12 candies. If there are 35 people in Annie's class in total, how much did Annie spend on candies, if one candy costs $0.1?
Let's be accurate as possible and think first.
8
There are 35 people in Annie's class, which means, she has 35 - 1 = 34 classmates.

Every classmate got 2 candies, so in total Annie gave out 34 * 2 = 68 candies.

In the beginning she had 68 + 12 = 80 candies.

One candy costs $0.

1, so Annie spend 80 * 0.

1 = $8 on candies.

.

So, the final answer is 8