Let the equal sides of the isosceles Δ ABC be x.
Given that the perimeter of Δ ABC = 50m.
Therefore, 2x + AC = 50 --- (1)
It is also given that the perimeter of Δ ABD = 40m.
Therefore, x + BD + AD = 40
BD is the median of the Δ ABC. Therefore, D is the midpoint of AC.
So AD = CD.
Or, AD = AC
Therefore,
Multiply both sides by 2.
2x + 2BD + AC = 80
From (1), 2x + AC = 50.
Therefore, 2BD + 50 = 80
2BD = 80 - 50
2BD = 30
BD = 15m.
ANSWER: 32 five-dollar bills
======
EXPLANATION:
Let x be number of $5 bills
Let y be number of $10 bills
Since we have total of 38 bills, we must have the sum of x and y be 38
x + y = 38 (I)
Since the total amount deposited is $220, we must have the sum of 5x and 10y be 220 (x and y are just the "number of" their respective bills, so we multiply them by their value to get the total value):
5x + 10y = 220 (II)
System of equations:
Divide both sides of equation (II) by 5 so our numbers become smaller
Rearrange (I) to solve for y so that we can substitute into (II)
Substituting this into equation (II) for the y:
We have 32 five-dollar bills
======
If we want to finish off the question, use y = 38 - x to figure out number of $10 bills
32 five-dollar bills and 6 ten-dollar bills
Answer:
6
Step-by-step explanation:
5% of 120 were late
= × 120
= 0.05 × 120
= 6