An urn contains marbles of four colors: red, yellow, blue, and green. All but 45 of the marbles are red; all but 45 are yellow; all but 45 are blue; and all but 60 are green. How many of the marbles are green?

5

Step-by-step explanation:

Let the number of

red marbles be r

blue marbles be b

yellow marbles be y and

green marbles be g

Let the Total number of marbles be T then

r + y + b + g = T

If all but 45 of the marbles are red then

y + b + g = 45

As such, r + 45 = T

all but 45 are yellow;

r + b + g = 45

As such, y + 45 = T

all but 45 are blue;

y + r + g = 45

As such, b + 45 = T

It means that the number of red, yellow and blue marbles are equal

Hence y = b = r

If all but 60 are green

y + b + r = 60

y + y + y = 60

3y = 60

y = 60/3 =20

This means that there are 20 yellow marbles, 20 red marbles and 20 green marbles

The total number of marbles T = 20 + 45 = 65

As such, g + 60 = T

g + 60 = 65

g = 65 - 60

= 5 marbles

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!