Anu, Bijay, Chetan, Deepak, Eshan, and Faruq are six friends. Each of them uses a mobile number from exactly one of the two mobile operators - Xitel and Yocel. During the last month, the six friends made several calls to each other.

Each call was made by one of these six friends to another. The table below summarizes the number of minutes of calls that each of the six made to (outgoing minutes) and received from (incoming minutes) these friends, grouped by the operators. Some of the entries are missing.

It is known that the duration of calls from Faruq to Eshan was 200 minutes.

Also, there were no calls from:

i. Bijay to Eshan,

ii. Chetan to Anu and Chetan to Deepak,

iii. Deepak to Bijay and Deepak to Faruq,

iv. Eshan to Chetan and Eshan to Deepak.

Q) What was the total duration of calls (in minutes) made by Anu to friends having mobile numbers from Operator Yocel?

To find the total duration of calls (in minutes) made by Anu to friends having mobile numbers from Operator Yocel, we can analyze the call duration flow between the two mobile operators, Xitel and Yocel.

First, we categorize the six friends based on their mobile operators:
1. Operator Xitel: Anu, Bijay
2. Operator Yocel: Chetan, Deepak, Eshan, Faruq

By definition, the total outgoing minutes from Xitel users to Yocel users must be equal to the total incoming minutes received by Yocel users from Xitel users.

From the table provided in the image, we can extract the incoming minutes from Operator Xitel to each of the Yocel users:
- Incoming minutes from Xitel to Chetan = 250
- Incoming minutes from Xitel to Deepak = 275
- Incoming minutes from Xitel to Eshan = 100
- Incoming minutes from Xitel to Faruq = 100

Thus, the total incoming minutes received by all Yocel users from Xitel users is:
$$250+275+100+100=725\text{ minutes}$$

This total incoming duration must equal the total outgoing duration from Xitel users to Yocel users. The only Xitel users are Anu and Bijay. Therefore:
$$\text{Outgoing from Xitel to Yocel}=\text{Outgoing from Anu to Yocel}+\text{Outgoing from Bijay to Yocel}$$

From the table, we read that the outgoing minutes from Bijay to Operator Yocel is 200. Let $A$ be the outgoing minutes from Anu to Operator Yocel. Setting up the equation:
$$A+200=725$$

Solving for $A$:
$$A=725-200=525$$

Therefore, the total duration of calls made by Anu to friends having mobile numbers from Operator Yocel is 525 minutes.

Correct Answer: 525