SOLUTION: Al has collected 60 insects, all of which are spiders,
dragonflies, and cicadas. Al counts 380 legs, and 140
wings altogether. How many insects are there in each
kind?
i want
Algebra.Com
Question 622272: Al has collected 60 insects, all of which are spiders,
dragonflies, and cicadas. Al counts 380 legs, and 140
wings altogether. How many insects are there in each
kind?
i want to solve this using equations
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
Al has collected 60 insects, all of which are spiders,
dragonflies, and cicadas. Al counts 380 legs, and 140
wings altogether. How many insects are there in each
kind?
---------------
c + d + s = 60 (# of creatures)
6c + 6d + 8s = 380 (# of legs)
2c + 4d = 140 (# of wings)
===============================
2c + 4d = 140 (# of wings)
c + 2d = 70
c = 70 - 2d
-----
Sub for c in eqns 1 & 2
--------
c + d + s = 60 (# of creatures)
70 - 2d + d + s = 60
-d + s = -10
----
6c + 6d + 8s = 380 (# of legs)
6(70 - 2d) + 6d + 8s = 380
420 - 6d + 8s = 380
-3d + 4s = -20
------
-d + s = -10
3d - 3s = 30
-3d + 4s = -20
----------------- Add
s = 10
************
d = 20
**********
c = 30
=================
Dragonflies have 4 wings.
Spiders are not insects.
RELATED QUESTIONS
A spider has 8 legs and no wings. A dragonfly has 6 legs and 2 pairs of wings. A cicada... (answered by checkley71)
Jamal has a collection of bugs. all of them are either ladybugs or spiders. he has a... (answered by ptaylor)
In Aunt Melly’s attics there are also spiders and ants, the total of 136 legs and 20... (answered by Boreal)
how many spiders are in a box which consist of 270 legs? with 1 spider having 8 legs and... (answered by ikleyn)
A spider has 8 legs. A dragonfly has 6 legs and 2 pairs of wings. A bird has 2 legs and 1 (answered by math_helper,Alan3354)
A boy had a box containing a total of 8 spiders and beetles. He counted 54 legs... (answered by Edwin McCravy)
In Aunt Peggy’s attics there are spiders and ants, the total of 160 legs. And, there is... (answered by Alan3354)
periodical cicadas are insects that emerge as adults the same year. one species that... (answered by ikleyn)
if i have a proof with with the given being AL=SK and i am trying to prove AS=LK and the... (answered by richard1234)