Correct answer is C..................
Answer:
n = 24
p(a) = 10/24
p(b) = 15/24
[ p(a) + p(b) - [p(a) ×p(b)] ] -1 = answer
[ 35/24 - 6/24 ] -1 = 39/24 - 24/24 = 5/24
ANSWER
B. 8
EXPLANATION
Volume of wooden crate is

The cubic blocks have side length,

The volume of each cubic blocks is,


Number of blocks that can go into the crate is,



Only one because there is one variable and the combined coefficients of x are non-zero.
(0.75(x+40)=0.70(x+20), 0.05x=14-30=-16, x=-320)