Answer: 
Step-by-step explanation:
Given
Length of the plank is 
Foot of the flank is 
away from the wall
Lizard climbs 2 m up the wall
from the figure, the two triangles are similar
So, the distance from the wall is
Cos(60) = cos(90 - 30) = sin(30) = 1/2
This should be what you want.
She originally had $400 in her bank account.
The 50w represents the amount she will put away each week.
Cost of the lawnmower bought by Sarah = $320
Amount of down payment made by Sarah = $100
Amount paid by Sarah in 12 months = (12 * 25) dollars
= 300 dollars
Total amount paid by Sarah = (300 + 100) dollars
= 400 dollars
Excess amount paid as interest by Sarah = (400 - 320) dollars
= 80 dollars
Actual yearly rate of interest paid by Sarah = (80/320) * 100 percent
= 25 percent
So 25% yearly interest was paid by Sarah. The correct option is option "C".
