Answer:
6 elephants and 3 kangaroos in the zoo.
Step-by-step explanation:
Number of animals = 9
Number of legs seen = 30
But an elephant has 4 legs, while a kangaroo has 2 legs.
Let the number of elephant be represented by E, and the number of kangaroo by K.
So that,
E + K = 9 .................. 1
4E + 2K = 30 ............. 2
Multiply equation 1 by 2 to have
2E + 2K = 18 ............ 3
Subtract equation 3 from 1
2E = 12
E = 6
Substitute the value of E in equation 1
E + K = 9
6 + K = 9
k = 3
Thus, there were 6 elephants and 3 kangaroos in the zoo.
