Question

Suha is going to buy 150 envelopes.

Here is some information about the cost of envelopes in two shops.
Letters2send
Pack of 25 envelopes for £3.49
Stationery World
Pack of 10 envelopes for £2.10
Buy 2 packs get 1 pack free
Suha wants to buy the envelopes as cheaply as possible.
Which shop should Suha buy the 150 envelopes from?
You must show how you get your answer.

Answer 1

Suha should buy the 50 envelopes from Letter2send.

Explanation:

Step 1:

At Letters2send, a pack of 25 envelopes costs £3.49. We need to determine how many packs will have 150 envelopes.

The number of packs =
`(150)/(25) = 6.`

So 6 packs of 25 envelopes will have 150 packs.

The cost for 150 envelopes =
`3.49 (6) = 20.94.`

So at Letters2send, 150 envelopes cost £20.94.

Step 2:

At the stationery word, if you buy 2 packs of 10 envelopes, you get a pack of 10 envelopes for free. So 3 packs cost £4.20. You get 30 envelopes for £4.20.

The number of 30 envelope packs =
`(150)/(30) =5.`

The cost for 150 envelopes =
`4.20 (5) = $21.`

So in the stationery world, 150 envelopes cost £21.

Step 3:

150 envelopes from Letters2send are cheaper than the stationery world so Suha should buy the envelopes from Letters2send.

Answer 2

Suha should buy 150 envelopes from shop 1 because the cost in shop 1 is 0.06 less shop 2.

Step-by-step explanation:

Total number of envelopes = 150

The cost of envelopes :

• Pack of 25 envelopes in shop 1 = 3.49
• Pack of 10 envelopes in shop 2 = 2.10
• Buy 2 packs get 1 pack free in shop 2.

Shop 1 :

The number of packs to buy 150 envelopes = 150 /25 = 6 packs

The total cost to buy 6 packs = 6 × 3.49 = 20.94

The cost of 150 envelopes in shop 1 is 20.94

Shop 2 :

The number of packs to buy 150 envelopes = 150 /10 = 15 packs

• For each 2 packs you get 1 pack free.
• 10 packs + 5 free packs = 15 packs

The total cost to buy 10 packs = 10 × 2.10 = 21

The cost of 150 envelopes in shop 2 is 21

The difference between shop 2 and shop 1 = 21 - 20.94 = 0.06

Therefore, the cost in shop 1 is 0.06 less than shop 2. So, Suha should buy 150 envelopes from shop 1.