Question

1. 5/ 8+root 7

A. 5/57
B. 5 root 7 /15
C. 5- root 7/8
D. 40- 5 root 7/ 57

My answer I had two was not sure A and D .

2. An object 8.1 feet tall casts a shadow that is 24.3 feet long. How long in feet would the shadow be for an object which is 17.4 feet tall?

A. 1.2 feet
B. 5.8 feet
C. 3.3 feet
D. 52.2 feet

I am not sure my answer was C and A.

Answer 1

5/(8+√7) = 5(8-√7)/(64-7) = (40-5√7)/57
So, (D). It should have been obvious that (A) was out, since it had no √√ involved.

Draw a diagram. Using similar triangles,

s/17.4 = 24.3/8.1
s = 52.2
(D)

All the others should have been easily eliminated since the given shadow was longer than the object casting it. Roughly 3 times as long. That ratio wojuld be the same for all objects at the same place.

Answer 2

Thanks Steve !!