SOLUTION: 6th grade word problem. My eleven year old has a page of problems like the one below. Since I am too old to remember if there is some logical way to solev these, I need to aks f

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Question 12160: 6th grade word problem.
My eleven year old has a page of problems like the one below. Since I am too old to remember if there is some logical way to solev these, I need to aks for your help.
Problem:
Leanne signed her new puppy up fr obedience classes. There were a total of 40 bodies in the class with 116 legs. How many of these were puppies and how many were people?

Can you help us?
Found 2 solutions by rapaljer, askmemath:
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = number of people
y = number of puppies

Since all the people and puppies alike have one body, this means that
x+y = 40

Assuming that all the people have 2 legs and the puppies all have 4 legs each,
2x + 4y = 116.

Solve the system of equations, either by elimination method or substitution.

R^2 at SCC

Answer by askmemath(368) About Me  (Show Source):
You can put this solution on YOUR website!
Let number of people= P
Number of dogs = D
P+D= 40
People have 2 legs ,Dogs have 4 So total number of legs
2P+4D = 116
P+D = 40
Multiplying the 2nd eqn with 2
2P+2D = 80
Subtracting from the first
2D = 36
D = 18
P=12
Check:
18x4 = 72
12x2 = 24
18+12 = 40
72+24 = 116 Yay!!