Mabel gave 1/6 of her stickers and another 20 stickers to Sue. She then gave 1/3 of the remainder and another 30 stickers to her sister. After that, she gave 1/2 of the remaining stickers and another 10 stickers to her brother. She had 20 stickers left. What was the total number of stickers she had at first?
To solve this problem, we'll work backwards, starting with the 20 stickers that Mabel had left.
Let's call the number of stickers Mabel had before giving any to Sue "x".
After giving 1/2 of the remaining stickers (20 stickers) and another 10 stickers to her brother, Mabel had 20 stickers left. So, before giving stickers to her brother, she had 20 * 2 + 10 = 50 stickers.
Before giving 1/3 of the remainder (50 stickers) and another 30 stickers to her sister, Mabel had 50 stickers left. So, before giving stickers to her sister, she had 50 * 3 + 30 = 180 stickers.
Before giving 1/6 of her stickers (1/6 of x) and another 20 stickers to Sue, Mabel had 180 stickers left. So, before giving stickers to Sue, she had 180 * 6 + 20 = 1,100 stickers.
Therefore, Mabel had a total of 1,100 stickers at the beginning.