1 - ⅜ = ⅝

So ⅝ of the total cards (which are the remaining cards) are made up of blue and yellow cards.

Since blue cards are twice the number of yellow cards,

blue cards make up ⅔ of the remaining cards and yellow cards ⅓ of the remaining cards

Fraction of cards that are blue

= ⅔ of the remaining cards
= ⅔ x ⅝ of the total cards
= 10/24
= 5/12

This is known as the branching method, or 'fraction of a fraction' method

Thank you for the clear explanation.

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