At an animal exhibit, 1/4 of the animals are reptiles. 5/8 of the remainder are mammals and the rest are amphibians. The number of male reptiles is 1/3 of the number of amphibians. There are 28 more amphibians than female reptiles. How many animals are there altogether at the exhibit?

Total number of animals --- x

Make a chart titled:
R(eptiles) M(ammals) and A(mphibians)

R = x/4
M = (5/8)((3x/4) = 15x/32
A = x - x/4 - 15x/32 = 9x/32

The number of male reptiles is 1/3 of the number of amphibians
----> MR = (1/3)(9x/32) = 3x/32
then FR = x/4 - 3x/32 = 5x/32

There are 28 more amphibians than female reptiles
9x/32 = 5x/32 + 28
4x/32 = 28
x = 224 <----- total number of animals

checking it all out
R = 224/4 = 56
M = 105
A = 63
this totals to 224, check!
The number of male reptiles is 1/3 of the number of amphibians
---> 3x/32 vs 1/3 9x/32
21 vs (1/3)(63) , yes, check

There are 28 more amphibians than female reptiles
A = 63
FR = 5x/32 = 35
Is 63 equal to 28 more than 35 ? sure is,

my answer is correct