# Glencoe Life Science

## Chapter 13: Mollusks, Worms, Arthropods, Echinoderms

### Use Percentages

 1 A strand of spider's silk can be stretched from 60 cm to 75 cm before losing its elasticity. Calculate the percent elasticity. A) 55% B) 30% C) 25% D) 50% 2 A strand of spider's silk can be stretched from 50 cm to 78 cm before losing its elasticity. Calculate the percent elasticity. A) 45% B) 56% C) 42% D) 58% 3 A strand of spider's silk can be stretched from 55 cm to 80 cm before losing its elasticity. Calculate the percent elasticity. A) 45% B) 50% C) 48% D) 40% 4 If the elasticity of a spider's silk is 30.7%, what was the original length of the strand if the difference between the two strands is 32 cm? A) 120 cm B) 100 cm C) 90 cm D) 104 cm 5 If the elasticity of a spider's silk is 30.7%, what was the original length of the strand if the difference between the two strands is 38 cm? A) 124 cm B) 120 cm C) 119 cm D) 98 cm 6 A strand of nylon can be stretched from 42 cm to 45 cm before losing its elasticity. Calculate the percent elasticity. A) 6.5% B) 7% C) 5% D) 7.8% 7 A strand of nylon can be stretched from 32 cm to 40 cm before losing its elasticity. Calculate the percent elasticity. A) 25% B) 28% C) 32% D) 40% 8 A strand of nylon can be stretched from 85 cm to 100 cm before losing its elasticity. Calculate the percent elasticity. A) 12% B) 15% C) 18% D) 25% 9 If the elasticity of nylon is 32%, what was the original length of the strand if the difference between the two strands is 38 cm? A) 99 cm B) 125 cm C) 129 cm D) 119 cm 10 If the elasticity of nylon is 40%, what was the original length of the strand if the difference between the two strands is 55 cm? A) 138 cm B) 145 cm C) 150 cm D) 120 cm