Let x = the total number of pennies her piggy bank can hold.
Then 2/3x = the number of pennies she started with
Then 2/3x - 80 = the number of pennies she has left after taking out 80 pennies.
Then 1/2x = the number of pennies she has left after taking out 80 pennies.
Build the equation.
2/3x - 80 = 1/2x
Subtract 1/2x from each side of the equation.
(2/3x - 80) - 1/2x = 1/2x - 1/2x
1/6x - 80 = 0
Add 80 to both sides of the equation.
(1/6x - 80) + 80 = 0 + 80
1/6x = 80
Divide both sides by 1/6.
(1/6x) / 1/6 = 80 / 1/6
x = 480
So, Linda's piggy bank can hold 480 pennies!
2 doctors is 8% of 25 total doctors.
6,2,8,4,and 0 are the only possible value of the ones digit, because
6*1=6, last digit is 6
6*2=12, last digit is 2
6*3=18, last digit is 8
6*4=24, last digit is 4
6*5=30, last digit is 0
6*6=36, last digit is 6
and the whole cycle goes over again.
You need to know more information, not just the length of the hypotenuse.
If you know the length of one leg use Pythagoras theorem to find the other.
If you know the value of one other angle use trigononemtry