The ratio of red marbles to blue marbles in a bag is 3:4 . If there are 42 marbles in the bag. how many marbles are red?

18 marbles

Step-by-step explanation:

Step 1

Express the fraction of each type of marble as a function of the total number of marbles as shown;

Let;

total marbles=x

red marbles=3/(3+4)=3/7x

blue marbles=4/7 x

But x=42 marbles

The total number of marbles for each type can be expressed as;

total number of red marbles=fraction of red marbles×total number of marbles

where;

fraction of red marbles=3/7 x

total number of marbles=42

replacing;

total number of red marbles=(3/7)×42=18 marbles

total number of blue marbles=fraction of blue marbles×total number of marbles

where;

fraction of blue marbles=4/7 x

total number of marbles=42

replacing;

total number of blue marbles=(4/7)×42=24 marbles

7745.2

Step-by-step explanation:

you need to multiply 67 by 578 which is 38726. then you divide it by 5. In short, you can just use calculator or you can use scratch paper.\