Browse Teasers
Search Teasers

Missing Price

Math brain teasers require computations to solve.

 Puzzle ID: #49348 Fun: (2.87) Difficulty: (1.08) Category: Math Submitted By: firefox99

When I went to the store, I purchased four items. The following shows the cost of three of the items:

\$1.50
\$3.00
\$4.00

The line to the checkout was pretty long, so to quench my boredom I started playing with my pocket calculator while waiting.

I found out, to my surprise, that the four prices of the four items I purchased added to the same number as I got when I multiplied the four prices together.

What was the price of the fourth item?

The three prices add to 1.50 + 3.00 + 4.00 = \$8.50.

The three prices multiply to 1.50 x 3.00 x 4.00 = \$18.00.

You might be able to see that adding another \$0.50 will take the total to \$9.00, and multiplying by another \$0.50 will take the product to \$9.00 also, but the answer can also be found using algebra. Let's call the unknown price P:
1.50 + 3.00 + 4.00 + P = 1.50 x 3.00 x 4.00 x P
8.50 + P = 18.00 x P
8.50 = 18.00 x P - P
8.50 = 17.00 x P
8.50/17.00 = P
P = 0.50.

Hide

What Next?

See another brain teaser just like this one...

Or, just get a random brain teaser

If you become a registered user you can vote on this brain teaser, keep track of
which ones you have seen, and even make your own.

 SRB_1807 Mar 05, 2012 Good one but pretty easy .... keep them coming ...cheers.... addspras Mar 27, 2012 like these easy fun ones..keep em coming! Babe May 20, 2012 No comment! castia123 May 20, 2012 yeah it is easy HABS2933 May 20, 2012 Nice and easy, perfect for a Sunday morning FatHead May 21, 2012 Not bad, but not much of a challenge, eh? edwardfalana Jan 26, 2013 Cool, but not much tasking. edwardfalana Jan 26, 2013 Cool, but not much tasking. raisin99 May 21, 2015 simple, but at least got the juices flowing! auntiesis May 21, 2015 I got the answer in seconds without using a calculator or paper and pen. Pretty easy. I like math problems, but this one was too easy. J-Mac May 25, 2015 Thanks for the puzzle! It was fairly easy to just figure it out without any formulae, but your algebra work has me stumped. All is fine until you go from: 8.50 = 18.00 x P - P to... 8.50 = 17.00 x P How do you get to 17.00 when dropping off the "- P"? Jim dalfamnest Jun 17, 2016 The algebra approach is quite predictable. What would be interesting would be for solvers to explain HOW they did it in "a few seconds"! I enjoyed this puzzle, even though it is easy.

Users in Chat : Proph, sciencesteven

Online Now: 8 users and 486 guests