INCEST- BOARD

jaime · Joined: 20 Jun 2007 Posts: 855 Location: UK

On a social networking site, Adam received a total of 115 messages over a period of five days, each day receiving four more messages than the day before. How many messages did he receive on the third day?

aleor · Joined: 31 Aug 2006 Posts: 121

23

being it is the 3rd day, the 4 less from the third day that is the second day cancels out the fourth day, and the same thesis for the first and fifth

Therefore easily worked out by 115 / 5

= 23

funkmonkey · Joined: 14 Apr 2007 Posts: 812

I did the math a little differently aleor, but ended up with the same answer.

I decided the first day would be our variable, x, and since every additional day adds 4, we end up with:

x+(x+4)+(x+ Cool

+(x+12)+(x+16)=115

Which simplifies as:

x+x+4+x+8+x+12+x+16=115

Which simplifies further as:

5x+40=115

Subtract both sides by 40:

5x=75

And divide both sides by five:

x=15

And then plug that into day three's formula x+8, and you end up with 23.

(Do I get extra credit for showing my work?)

jaime · Joined: 20 Jun 2007 Posts: 855 Location: UK

Congrats, aleor and funkmonkey. You both get an A+, and fm gets a distinction for making my head hurt with his workings!!

aleor · Joined: 31 Aug 2006 Posts: 121

we should give Jaime special I-B brand Ibuprofen Smile