A variation on a classic for your algebra group!
J is as old as K was when J was half the age he'll be in 10 years. If K is y yrs old, express J's current age in terms of y.
Want answer and detailed solution sent to your inbox? By now you should know what you have to do. Join the other teachers who have figured it out...
So you're probably thinking this question is either too hard or irrelevant in the Common Core. I beg to differ!
Before having students attempt to solve this algebraically I would encourage my students to experiment with numerical values. For example suggest a value for y, say y=40 and have them guess some values for x, J's current age. I'm sure you'd agree that this is still a challenging problem but someone will probably guess the correct value, x=30. In fact just verifying that 30 is correct is formidable enough!
Is making a table still a good idea for organizing information? I'll let you decide...
Present 10 yrs from now
J x x+10
K y y+10
So is there still a value to these "un-real" types of puzzle problems? Do you see the benefits that I do?