Question

24 iron rods of the same size weigh \[240kg\] . What will be the weight of \[20kg\] such iron rods?
1). \[200kg\]
2). \[2000kg\]
3). \[120kg\]
4). \[100kg\]

Answer 1

Hint: In this question we have to find the weight of \[20kg\] iron rods and we have given \[24\] iron rods of the same size weigh, so firstly we will find out the weight of one rod and then we can easily find out the value of \[20kg\] iron rods easily and we can check that which option is correct.

Complete step-by-step solution:
The unitary method is a method for determining the value of a single unit from the value of many units and multiple units from the value of a single unit. It's a method that we employ for the majority of math calculations. You can use this strategy to solve issues on ratio and proportion, algebra, geometry, and other subjects.
We find the value of a single unit from the value of many units and the value of multiple units from the value of a single unit using the unitary technique.
We always count the value of a unit or one quantity first in the unitary approach, and then we calculate the values of more or less quantities. As a result, this procedure is called the unitary method. Because unitary methods produce two types of variations, there are two types of unitary methods:
Direct Variation
Indirect Variation
Direct Variation:
The direct relationship between two quantities is described by this kind. To put it another way, if one amount increases, the other quantity increases as well, and if one quantity declines, the other quantity lowers as well.
Indirect Variation:
The indirect relationship between two quantities is described by this type. To put it another way, if one quantity rises, the other decreases, and if one quantity reduces, the other increases.
Now according to the question:
We have given that \[24\] iron rods are of weight \[240kg\]
Hence the weight of one iron rod be:
\[= \dfrac{240}{24}\]
\[= 10kg\]
Hence the weight of \[20\] rods will be:
\[= 20\times 10\]
\[= 200kg\]
Hence option \[(1)\] is correct as the weight of \[20kg\] iron rod is \[200kg\].

Note: Students you must note that multiplying the value of one quantity by the number of quantities yields the value of multiple quantities. By dividing the value of many quantities by the number of quantities, one can find the value of one and always write the things to be computed on the right-hand side and the things known on the left-hand side to simplify things.