A deck of 52 playing cards is about 3 quarters of an inch thick. What is the thickness of each card in millimetres?

Question

this is a question about measurements more specifically conversion between two units of measurement.

Answer 1

Use the following:

 

1 inch = 2.54 centimeters

 

1 centimeter = 10 millimeters

 

52 cards = 0.75 inches

 

1 card *  0.75 in  * 2.54 cm * 10 mm = _________ mm

             52 cards       1 in        1 cm

Answer 2

There are about 25.4 mm in an inch

 

3/4" in mm is 25.4 * .75 = 19.05 mm

 

If there are 52 cards, each card is 19.05/52 = 0.366 mm thick

Answer 3

The key to these units conversions is to keep multiplying by 1 - being very careful how you choose to represent 1, until the units are correct.  Here are some examples:

 

12-in/1-ft   = 1  ( they are the same length, just different units)

 

1-yd/3-ft  =  1   (same length, different units)

 

60-sec/1-hour  = 1   (same amount of time, just different units)

 

and the one you need is 

 

1-in/2.54-cm = 1    (or 1 inch = 2.54 cm)

 

 

Start with 52 cards.  They want to know the thickness of just one card, so we need to divide by 52.

 

52 cards= 0.75"

----          --------

52                52

 

1 card thickness  = 0.75 inches / 52 cards

 

Now we will convert:

 

0.75 in              2.54 cm                (0.75)(2.54) cm

--------      *   --------------    =   -------------------------    "inches" cancel, now cm/card   

52 cards              1 in                          (52 cards)

 

 

But we need millimeters per card, so now we need the ratio for 1 to have mm/cm   this way the cm will cancel and the mm will be on top.

 

100 cm          1 meter                        100 cm

---------  *  --------------          =    -------------                (the "1 meter"s cancelled)  = 

1 meter       1000 millimeters            1000 millimeters  

 

1 cm

------                = 1    (same length, different units)

10 millimeters 

 

 (0.75)(2.54) cm          10 millimeters                     (0.75)(2.54)(10) millimeters
 --------------        *  --------------------------   =   -------------------------
(52 cards)                       1 cm                                       (52 cards) 

 

= 0.366346 millimeters per card