At a zoo, 1/3 of the animals are birds, 4/9 are mammals, and the rest are reptiles and amphibians. What fraction of animals at the zoo are reptiles and amphibians?

1/3 + 4/9 = 7/9

that help?

2/9

To find the fraction of animals that are reptiles and amphibians, we need to determine the fraction that is neither birds nor mammals. We can start by calculating the fraction of animals that are birds and mammals:

Fraction of animals that are birds = 1/3
Fraction of animals that are mammals = 4/9

To find the fraction of animals that are neither birds nor mammals, we can subtract the sum of these two fractions from 1 (since the remaining fraction represents the animals that are neither birds nor mammals):

1 - (1/3 + 4/9)

To add fractions, we need to find a common denominator. The least common multiple (LCM) of 3 and 9 is 9. So, we rewrite the fractions with the common denominator of 9:

1 - (3/9 + 4/9)

Now, we can subtract the fractions:

1 - (7/9)

To subtract fractions with the same denominator, we subtract the numerators and keep the denominator the same:

1 - 7/9 = (9/9) - (7/9) = 2/9

Therefore, the fraction of animals at the zoo that are reptiles and amphibians is 2/9.