Answer: 1:1
Step-by-step explanation:
Let r be the radius and h be the height of a cylinder.
Formula: Curved surface area of cylinder =
Now, if radius of a cylinder is doubled and its height is halved, then new radius will be R= 2r and new height will be
Now, new surface area =
Ratio of curved surface areas :
Hence, the ratios of their surface areas = 1:1 .
Answer:
Probability that one of them is mathematics and other two are either physics or history books = 0.51
Step-by-step explanation:
Given - A student needs to select 3 books from 3 different mathematics, 3 different physics and 1 history books.
To find - What is the probability one of them is mathematics and other two are either physics or history books ?
Solution -
Given that,
A student needs to select 3 books from 3 different mathematics, 3 different physics and 1 history books.
So,
Total number of books = 3 + 3 + 1 = 7
The student has to select 3 books
So, Total number of ways = = 35
So,
Probability that one of them is mathematics and other two are either physics or history books is -
=
=
=
= 0.51
⇒Probability that one of them is mathematics and other two are either physics or history books = 0.51