How many did each service deliver to Erika?

Question

At work one day, Erika recieved 21 packages. Speedy delivery delivered twice as many as Ralph Express while Ralph Express deilivered 3 more than sendquick package service. How many did each service deliver to Erika?

Speedy delivery?
Ralph Express?
sendquick package service?

Answer 1

:) u have to learn to translate the word problem into mathematical equations:

S = Sendquick
R = Ralph = 3+S
Sp = 2R = 2(3+S)

all these add up to 21.

so...

S + (3+ S) + 2(3+S) = 21

S + 3+ S + 6 + 2S= 21

4S + 9 = 21

4S = 12

S = 3

ok, so Sendquick = 3. plug it in the earlier equations:

Ralphs = S + 3 = 3 + 3 = 6

Speedy = 2(R) = 2*6 = 12


TADA!

Speedy = 12
Ralphs = 6
Sendquick = 3

Answer 2

Sendquick = 3
Ralph = 6
Speedy=12

Here is how to set it up:

Let q = the number of packages delivered by Sendquick,
let r = the number of packages delivered byt Ralph Express,
and
Let s = the number of packages delivered by Speedy

Then, set up the following 3x3 system of equations:

s+r+q=21
r=3+q
s=2*r

Answer 3

Speedy =S
Ralph = R
SendQuick = Q

21=S + R + Q
S=2R
21=3R+Q
R=Q+3
21=3(Q+3) +Q
21=3Q+9+Q
21=4Q+9
12=4Q
3=Q
R=6
s=12