Answer:
6x: 312
x: 52
Explanation:
Let the deck be denoted by x then
6x: 312
There are 312 cards in 6x decks
In 1 deck x there are 312/6= 52 cards
6x: 312
6x/6: 312/6 Cancelling both sides by 6
x: 52
In ratio both the sides are divided by the same number to get equivalent fractions.
In 1 deck there are 52 cards