BOB and the ball

BOB and the ball


The question is - 

If a bat and a ball together cost $1.10 and the bat costs $1.00 more than the ball –
how much does the ball cost?


The answer is - 

Five cents.

The ball costs five cents.
The bat costs one dollar and five cents.
The bat costs one dollar more than the ball.
Together they cost one dollar and ten cents.

That’s OK –

BOB got it wrong, too.

BOB was taught to show your work –

SO she will give you two methods to solve this problem -

METHOD #1 – Algebra – 

BOB LOVES ALGEBRA –
IT’S SO LOGICAL -
BUT IT IS THE LONG WAY –
AND most people HATE Algebra -
So -
BOB won’t use “X” –
Instead - she will just use (BALL) –
Maybe that will make more sense to those of you who are math-challenged.

We want to know the cost of the ball – so that’s - (BALL)

Ball = (BALL)

The BAT costs one dollar more than the ball –

Bat = (BALL + $1.00)

Together they cost ($1.00 + $.10)

So –

Ball + Bat = ($1.00 + $.10)

Substitute for Ball and Bat -
(BALL) + (BALL + $1.00) = ($1.00 + $.10)

Simplify – get rid of the parentheses -
BALL + BALL + $1.00 = $1.00 + $.10

Add the balls together -
2 BALLS + $1.00 = $1.00 + $.10

Get rid of the dollar on each side - 
Leaves us with -
2 BALLS = $.10

So –
1 BALL = $.05


METHOD #2 - Talk it out -
The short way -

Together the ball and bat cost one dollar and ten cents.
If the bat costs one dollar more than the ball –
The dollar belongs to the bat.
That leaves the ten cents.
Except for the dollar - the bat and ball cost the same.
The bat is half of the ten cents – the ball is the other half.
Half of ten cents is five cents.
The ball costs five cents.
The bat costs one dollar and five cents.
Together they cost one dollar and ten cents.


Any problem is easy – if you know the answer.  ;))