8 – Cassie does not like to say her age. When someone asks, her mother answers for her. Cassie's mother says, "I'm seven times as old as Cassie now. In 20 years, Cassie will be half the age that I will be then." How old is Cassie now?
10 – In your cellar, there are three light switches in the ‘off' position. Each switch controls one of three light bulbs on the floor above it. You may move any one of the switches but you may only go upstairs to inspect the bulbs once. How can you determine the switch for each bulb with only one inspection?
EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.
This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.
To send comments or feedback to our Editorial Team regarding the content please email us at firstname.lastname@example.org. Our Health Library Support team will respond to your email request within 2 business days.