200 books ; 75% decrease

the answer is 150 because you figure that 75 is 3/4 of 100. and 1/4 of 200 is 50. or you can do

.75*200=150

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,