Question

Cards in a pack are black or red in the ratio Black : red =2:5

What fraction of the cards are red

7/10. 2/5. 5/7. 2/7
A. B. C. D

Answer 1

Answer:

C. 5/7 will be the answer

Hope it helps..

Answer 2

Fraction of Red cards in given question is 2/7

(option D)

Step-by-step explanation:

$\text{ There are only two colours of cards, Red and Black}\\\\\textbf{The ratio of cards as Red : Black = 2 : 5 (given)}\\\\\text{It means in total of 7x cards , 2x cards will be Red and 5x cards will be Black}$

$\textbf{Formula of Fraction=}\frac{\textbf{Number of favourable parts}}{\textbf{Total parts}}$

$\text{For finding the fraction of Red cards}\\\text{ we get to know the total number of cards and number of Red cards}$

$\textbf{We know that Number of Red cards = 2x}\\\textbf{Number of total cards = 7x}\\\\\text{putting these values in Formula of Fraction given above}$

$\textbf{FRACTION OF RED CARDS=}\frac{\textbf{2x}}{\textbf{7x}}\\\\\\\textbf{FRACTION OF RED CARDS=} \frac{\textbf{2}}{\textbf{7}}\\\textbf{So the correct option is D (2/7)}$