- A rope makes 70 rounds of the circumference of a cylinder whose radius of the base is 14 cm.
- Number of rounds that a rope can go round a cylinder with radius 20 cm can be figure out in this way.
Explanation
Two given entities here are
- Radius
- Rounds
To determine the relation here, let suppose; Number of rounds that a rope can go round a cylinder with radius 20 cm = y
Case
Radius Rounds
14 70
20 y
- More radius means less rounds.
- Less radius means more rounds.
This clearly indicates that there is inverse relation.
Direct/Indirect relation tells how the equation will be written.
14 : 20 :: y : 70 ________ (i)
20 x y = 14 x 70 ________ (A)
After simplifying equation (A), we can easily figure out the value of y (y = 49)
To Find
Number of rounds that a rope can go round a cylinder with radius 20 cm = ?
Solution
Method I
Let suppose
Number of rounds that a rope can go round a cylinder with radius 20 cm = y
Radius Rounds
14 70
20 y
- Relation between radius and rounds is inverse.
So
14 : 20 :: y : 70
20 x y = 14 x 70
20y = 980
y = 980/20
y = 49
Number of rounds that a rope can go round a cylinder with radius 20 cm = 49 rounds answer
Method II
Number of rounds that a rope can go round a cylinder with radius 14 cm = 70 rounds
Number of rounds that a rope can go round a cylinder with radius 1 cm = (70 x 14) rounds
Number of rounds that a rope can go round a cylinder with radius 1 cm = 980 rounds
Number of rounds that a rope can go round a cylinder with radius 20 cm = 980/20 rounds
Number of rounds that a rope can go round a cylinder with radius 20 cm = 49 rounds
Number of rounds that a rope can go round a cylinder with radius 20 cm = 49 rounds answer
Conclusion
A rope makes 70 rounds of the circumference of a cylinder whose radius of the base is 14 cm. 49 times it can go round a cylinder with radius 20 cm.
