Tiffany starts with $2300 in her saving account. If she spends $85 per week, how long will it take her to run out of money

Question

Can you help me solve this question using guess check generalize to solve

Answer 1

Start with: $2300 

$85/week 

 

Guess how many weeks you think she may have. Say 30 weeks. 

Plug into what you have. 

 

$85 x 30weeks = 2550

 

This number is too high right?

So pick a lower number.  20 weeks

Plug it in. 

 

$85 x 20weeks = 1700

 

This is too small. 

So you now know it is between 20 and 30. Now narrow your range. 25 weeks

Plug it in!

 

$85 x 25weeks = $2125

 

Closer. But still too low. You want to get the closest whole number of weeks to over $2300.

Now check all number between your answer. (26, 27, 28, 29)

 

$85 x 26weeks = $2210

$85 x 27weeks = $2295

$85 x 28weeks = $2380

$85 x 29weeks = $2465

 

28 weeks is correct! Now to Check!!!

 

 

 

$85/week

start amount: $2300

find how many weeks (x)

 

2300   =    85   

   x            1

 

Solve for x.

 

2300(1) = 85(x)

2300 = 85x

x = 27.08 weeks

 

(round up to 28 weeks since it is over 27 weeks and we need whole numbers.)