Easy la...
Hotel is $30 bucks, but after discount is only $25. The $5 given
back to the 3 friends, whom each took back $1, and the remaining $2
given to the bell boy.
Therefore, it seems that you can just minus $1 from the $10 that
each friend paid, meaning that they each paid $9 bucks (which is
true). Therefore ($9 x 3) + $2 = $29, and thus there is a missing
on $1. Theoretically it may seems right but its actually wrong, and
it will be explained below.
Actually the $1 is "hidden" in the $25 paid for the hotel. $25
divided by 3 is actually $8.33. Therefore each friend actually paid
$8.33 for the hotel.
To solve the mystery, ($8.33 x 3) + ($1 x 3) + $2 = $30
To further solve the mystery: From the $5 discount given back to
the boys, they should actually received back $5/3=$1.67. But
instead, they each decided to take back only $1. Therefore $1.67 -
$1 = $0.67. Which means, they each forgo only $0.67. Therefore
$8.33 (hotel) + $0.67 (tips) = $9 per person.
Each friend actually paid $9 each. Based on the original $10
given by each friend, $8.33 went into the hotel, $1 went back into
their wallet and $0.67 which will adds up to the $2 tip given
to the bell boy.
TS should not have written ($9 X 3) +$2 = $29, and ask us where
the remaining $1 has gone. Because the $9 is already inclusive of
the tips, and thus the $2 should not even be there in the first
place.. Therefore it should actually be ($9 x 3) + $3 = $30. TS
should replace the $2 with $3, which was what the 3 friends took
back in total.
Problem Solved!!!!
