Answer:Fred has 13 9/10 minutes left for question C
Step-by-step explanation:
The total time that Fred has to do the three-problem quiz is 30 minutes.
He spent 10 7/10 minutes on question A. Converting 10 7/10 minutes to improper fraction, it becomes 107/10 minutes.
He spent 5 2/5 minutes on question B. Converting 5 2/5 minutes to improper fraction, it becomes 27/5 minutes.
Total time that Fred spent on question A and question B is
107/10 + 27/5 = (107 + 54)/10
= 161/10 minutes.
The amount of time that he has left for question C would be
30 - 161/10 = (300 - 161)/10 = 139/10
= 13 9/10 minutes
Answer:
It is 30 because it is the only one that makes sense if you do the math
<u>Answer-</u>
<em>The correct answer is</em>
<em>∠BDC and ∠AED are right angles</em>
<u>Solution-</u>
In the ΔCEA and ΔCDB,

As this common to both of the triangle.
If ∠BDC and ∠AED are right angles, then 
Now as
∠BCD = ∠ACE and ∠BDC = ∠AED,
∠DBC and ∠EAC will be same. (as sum of 3 angles in a triangle is 180°)
Then, ΔCEA ≈ ΔCDB
Therefore, additional information can be used to prove ΔCEA ≈ ΔCDB is ∠BDC and ∠AED are right angles.
Answer:
2: The perimeter of the base is 37 units.
Step-by-step explanation:
1. A = LW = 21 * 16 = 336 units^2 True
2. P = 2(L + W) = 2(21 + 16) = 2(37) = 74 units False
3. H = 21 units True
4. SA = 2LW + 2H(L + W) = 2(21)(16) + 2(21)(21 + 16) = 2226 units^2 True