Here are the answers and walkthrough to Stupid Test Level 15 Question 7 – Mary had a number of cookies. After eating one, she gave half the remainder to her sister. After eating another cookie, she gave half of what was left to her brother. Mary now had only five cookies left. How many cookies did she start with?

• Simple work backwards:(((5×2)+1)x2)+1=23

Answer

• 23

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