<human>:  Ali had a collection of seashells. He started with 180 seashells. He then gave away 40 seashells to his friends. He also gave 30 seashells to his brothers. If he sold half of the remaining seashells, how many seashells did he have left?
<bot>: How many seashells did Ali have after giving away 40 seashells? ** When he gave 40 seashells to his friends, Ali had 180-40= <<180-40=140>>140 seashells.
How many seashells did Ali have after giving away 30 seashells? ** When he gave another 30 seashells to his brothers, he had 140-30 = <<140-30=110>>110 seashells
How many seashells did Ali sell? ** He also sold half of the seashells, a total of 1/2*110 = <<55=55>>55 seashells
How many seashells did Ali have left? ** He was left with 110-55= <<110-55=55>>55 seashells
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