Arithmetic

Step 1: Let the total number of pages be .
Rani has read of the book, and there are still 80 pages left to read. The remaining portion of the book, therefore, is .

Step 2: Set up the equation.
The remaining pages are given as 80. Therefore, we can write the equation:

Step 3: Solve for .
To find , multiply both sides of the equation by :

Step 4: Conclusion.
Thus, the total number of pages in the book is .

Final Answer: 200.

Step 1: Formula for Simple Interest.
The formula for calculating simple interest is: Where: is the principal amount, is the rate of interest per annum, and is the time in years.

Step 2: Apply the given values.
Here, , , .
Now substitute the values into the formula:

Step 3: Conclusion.
Therefore, the simple interest is ₹ 2400.

Final Answer: ₹ 2400.

Step 1: Understanding the expression.
The problem asks us to evaluate the product of the cube roots of 1372 and 1458. This can be simplified using the property of cube roots:

Step 2: Multiply the numbers under the cube root.
We first multiply 1372 and 1458:

Step 3: Take the cube root of the product.
Now, we find the cube root of 2000256:

Step 4: Conclusion.
Therefore, the correct answer is 126.

Final Answer: 126.

Step 1: Understanding the problem.
Gopi sold the watch to Ibrahim at a 12% gain. Ibrahim then sold it to John at a 5% loss. We are given that John paid ₹ 1,330. We need to determine the price at which Gopi sold the watch to Ibrahim.

Step 2: Let the price at which Gopi sold the watch be x.}
Gopi's selling price to Ibrahim = . Ibrahim's selling price to John = , since he sold it at a 5% loss.

Step 3: Relating the final price.
We know that John paid ₹ 1,330 for the watch, so: Solving for , we get:

Step 4: Conclusion.
Therefore, Gopi sold the watch to Ibrahim for ₹ 1400.

Final Answer: ₹ 1400.