Correct Option:Option B
Solution:The given expression is:

cos(3x) can be written as cos(2x +x). Expanding it, we get:

Using this value of cos(3x) in given equation, we get:
Answer: 40 times
Step-by-step explanation:
Given: Total planks = 20
By using integers, Steps forward is represented by +5, Steps backward s represented by -4.
After first set of two steps ( one forward another backward), 5-4 =1 step forward is captured.
For 20 planks , we require 20 such sets, i.e. he will do this 2x 20 times i.e. 40 times.
Hence, he will do this 40 times to reach the other side.
Answer: 0.25
Step-by-step explanation:
The relative frequency of the customers that buy computers is equal to the number of customers that bought a computer divided the total number of customers that entered the shop.
p = 25/100 = 0.25
If we take this as the probability, then the probability that the next customer that enters the shop buys a computer is 0.25 or 25%