word problem help

[kwhitmer0001]

Shelly is planning on bringing a great deal of film on an overseas photo safari. A photography store is selling 6-packs of film for $39 and 15-packs of the same film for $88.

If she wishes to purchase only the 6-packs and 15-packs and to spend a maximum of $400 on film, what is the maximum number of rolls she can purchase?

What will be the cost? If she can purchase the maximum number of rolls in more than one combination of packs, determine the lowest cost available.

 

[kwhitmer0001]

confused

I know if she has $400 she can purchase 10 of the 6-packs at $38 each or 4 of the 15-packs for $88 each. Am unsure of how to get what they are asking for tho.

 

[Deleted member 4993]

I know if she has $400 she can purchase 10 of the 6-packs at $38 each or 4 of the 15-packs for $88 each. Am unsure of how to get what they are asking for tho.

To buy maximum number of film - she should buy max. number of 15 packs with as little as money left from $400.

Make a table

If she buys 4 - 15 packs ($352) - she can buy 1 more 6 pack ($38) with the money left (and still have $10 left) - total 66 packs of film

If she buys 3 - 15 packs ($264) - she can buy 3 more 6 pack ($114) with the money left (and still have $22 left) - total 63 packs of film

If she buys 2 - 15 packs ($176) - she can buy 5 more 6 pack ($190) with the money left (and still have $34 left) - total 60 packs of film

If she buys 1 - 15 packs ($88) - she can buy 7 more 6 pack ($266) with the money left (and still have $46 left) - total 57 packs of film

Now decide......