Maths question help!

Nicole has a bag of 30 marbles
5 types= red, blue, pink, orange and yellow

there is one more red marble than yellow
there are the same number of red and pink marbles
there are four more red than blue marbles
there are five more red marbles than orange marbles

there are 30 marbles in the bag
how many yellow marbles are there in the bag? Thank you!

Set up a system of equations and see what you can do. Use r = red, b = blue, p = pink, o = orange, y = yellow

r+b+p+o+y = 30

r = y + 1
r = p
r = b + 4
r = o + 5

I'd take these four equations and solve them all for their respective variable.
so ->
y = r - 1
p = r
b = r - 4
o = r - 5

Go back to this sum equation:
r+b+p+o+y = 30

Replace everything, this will give you everything in terms of r.

r + (r-4) + (r) + (r-5) + (r-1) = 30
5r - 10 = 30
5r = 40
r = 8

Bringing back
r = y + 1
8 = y + 1

y = 7

Hi,

x = # of yellow marbles
x + 1 = # of red or pink
x - 3 = # of blue
x - 4 = # of orange

x + x + 1 + x + 1 + x - 3 + x - 4 = 30

5x - 5 = 30

5x = 35

x = 7 <==ANSWER for # of yellow

8 red, 8 pink, 4 blue. 3 orange, and 7 yellow in total

I hope that helps!! :-)

r =red
b = blue
p = pink
o = orange
y = yellow
total marbles =30
r + b + p + o + y = 30
the next 4 lines you give me, i just switched around to make the colors equal to each other
y + 1 = r ----> y = r-1
r = p ----> r = p
b + 4 = r -----> b = r -4
o + 5 = r ----> o = r - 5
now plug in all these variables to solve for r
r + (r-4) + (r) + (r-5) + (r-1) = 30
5r -10 = 30
5r = 40
r = 8
plug r = 8 into y= r-1
y = 8 - 1
y =7 ANSWER!!!!

r=y+1
r=p
r=b+4
r=o+5
r+y+p+b+o=30
2r+y+b+o=30--p=r
2r+(r-1)+(r-4)+(r-5)
5r-10=30
5r=40
r=8
8=y+1--Back to your statement("there is one more red marble than yellow")
y=7

There are 7 yellow.