Interesting math: when the lizard is 15cm long, it weighs 15g. How much does it weigh when it is 20 cm long? To solve the process, help.
"Weight is proportional to its volume, and volume is proportional to the cube of body length", so we can get that the ratio is (15÷ 15? ) ≈0.0044, now the lizard is 20, so its weight is 20? ×0.0044=35.2, weighing about 35.