There is a total of 364 marbles in a jar. The ratio of blue to red marbles is 3:4. How many red
marbles do you have?

Example 1:

In a bag of red and green sweets, the ratio of red sweets to green sweets is 3:4. If the bag contains 120 green sweets, how many red sweets are there?

Solution:

Step 1: Assign variables :

Let x = red sweets

Write the items in the ratio as a fraction.

red/green

Step 2: Solve the equation

Cross Multiply

3 × 120 = 4 × x

360 = 4x

Isolate variable x

x=360/4

There are 90 red sweets.

Example 2:

John has 30 marbles, 18 of which are red and 12 of which are blue. Jane has 20 marbles, all of them either red or blue. If the ratio of the red marbles to the blue marbles is the same for both John and Jane, then John has how many more blue marbles than Jane?

Solution:

Step 1: Sentence: Jane has 20 marbles, all of them either red or blue.

Assign variables:

Let x = blue marbles for Jane

20 – x = red marbles for Jane

We get the ratio from John

John has 30 marbles, 18 of which are red and 12 of which are blue.

red/blue

We use the same ratio for Jane.

red/blue

Step 2: Solve the equation

Cross Multiply

3 × x = 2 × (20 – x)

3x = 40 – 2x

Isolate variable x

x=40/5

John has 12 blue marbles. So, he has 12 – 8 = 4 more blue marbles than Jane.

John has 4 more blue marbles than Jane.

Step-by-step explanation:

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!