Question

Cost of one meter of cloth is Rs 35.80. What will be the cost of 9.8 meters of cloth?

Answer 1

Hint: we have to find the cost of 9.8 meters of cloth and the cost of 1 meter cloth is given in the question. So, we will use the unitary method and we will find the cost by multiplying the cost of 1 meter cloth by the meters of cloth whose cost we need to find.

Complete step-by-step solution:
Unitary method says that if the cost of x item is Rs. y then cost of 1 item is $\dfrac{y}{x}$---(1). Now if we wish to calculate cost of z items then it will be $z \times \dfrac{y}{x}$-----(2)
Now we will use this principle in our question to calculate the cost of 9.8 meters of cloth.
In the question we are already given the cost of 1 meter of cloth so we don’t need to use equation (1). Now we will use equation (2) to calculate the cost of 9.8 meters of cloth.
Cost of 1 meter cloth is Rs. 35.80.
We have to find the cost of 9.8 meters of cloth. So, we will multiply 9.8 by 35.80 to find the answer.
Cost of 9.8 meters cloth $ = 35.80 \times 9.8$
Cost of 9.8 meters cloth$ = Rs350.84$
So, the cost of 9.8 meters cloth is Rs 350.84.

Note: The calculations in this question include decimals. So, the calculations are to be performed very carefully and if there is zero at the last digit after the decimal it does not mean anything. For example: 350.840 can be written as 350.84, it does not make any difference.