Answer:
They will need $47 more to reach their goal of $215
Explanation:
since we know Ixtli has saved $126 and that her sister has saved 3 times less than that, we can find how much her sister has saved by taking a third of 126. This will give you that her sister has saved $42. Altogether they have a total of $168. Take the total amount they want to have ($215) and subtract how much they currently have. This will result in $47 short of $215