Question

7. There are 25 dinosaurs in a specific Jurassic World Exhibit. Some are T-Rexes and some
are triceratops. There are 92 legs total in the exhibit. Create 2 equations to represent this
situation. How many of each type dinosaur is there? (Assume that all of the dinosaurs have
the correct number of limbs.)

Answer 1

9514 1404 393

Answer:

• r + t = 25
• 2r +4t = 92
• 4 T-Rex, 21 triceratops

Step-by-step explanation:

For this we have to assume that the T-Rex has only 2 legs. Let r represent the number of T-Rex, and t represent the number of triceratops. The problem statement tells of two relationships:

  r + t = 25 . . . . . . total number of dinosaurs in the exhibit

  2r +4t = 92 . . . . total number of legs in the exhibit

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Multiplying the second equation by 1/2 and subtracting the first, we find ...

  (1/2)(2r +4t) -(r +t) = 1/2(92) -(25)

  t = 21 . . . . . . simplify

  r = 25 -21 = 4

There are 4 T-Rex, and 21 triceratops.