Answer:
7
Step-by-step explanation:
Number of shells found = 14
Number of shells lost equals number of shells left :
Let Number of shells lost = x
Using the relation:
Number of shells lost = Number of shells left
x =number of shells found - number of shells lost
x = 14 - x
x + x = 14
2x = 14
x = 14 / 2
x = 7
Number of shells left = 14 - x = 14 - 7 = 7
