Sandy and Mandy together complete eight-thirteenths (8/13) of a job, and the remaining work is completed by Andy alone. If the total payment for the job is Rs 2600 and the workers are paid in proportion to the amount of work done, what is Andy's share in rupees?

Introduction / Context:
This is a work and wages problem about three workers, Sandy, Mandy, and Andy. The first two complete a known fraction of the work together, and the last worker completes the rest. We are given the total amount paid for the whole job and must determine Andy share under the assumption that payment is proportional to work performed. Questions like this connect time and work concepts to simple financial division.

Given Data / Assumptions:

• Sandy and Mandy together complete 8/13 of the job.
• Andy completes the remaining part of the job.
• Total payment for the job is Rs 2600.
• Payment is divided in the ratio of work done by each group or person.
• Total work is considered as 1 full job.

Concept / Approach:
When payment is proportional to work done, each person share is equal to total payment multiplied by the fraction of work that person completed. First we find the fraction of work done by Andy, which is the remaining work after Sandy and Mandy have finished their part. Then we multiply Andy fraction of work by the total payment to get his share. This is a direct application of ratio and proportion combined with the concept of fractions of work.

Step-by-Step Solution:
Step 1: Let total work be 1 job. Step 2: Sandy and Mandy together complete 8/13 of the work. Step 3: Remaining work is 1 - 8/13 = 5/13 of the job. Step 4: The remaining 5/13 of the job is done by Andy alone. Step 5: Andy fraction of total work = 5/13. Step 6: Total payment for the job is Rs 2600. Step 7: Andy share = (fraction of work done by Andy) * total payment. Step 8: Andy share = (5/13) * 2600. Step 9: Compute 2600 / 13 = 200 and then 200 * 5 = Rs 1000.

Verification / Alternative check:
We can also think in terms of total shares. Suppose total work of 1 is divided into 13 equal parts. Sandy and Mandy share 8 parts, and Andy share 5 parts. Total payment Rs 2600 divided by 13 parts is Rs 200 per part. Then Andy, with 5 parts, receives 5 * 200 = Rs 1000, while Sandy and Mandy together share 8 * 200 = Rs 1600. The sum 1600 + 1000 = 2600 matches the total payment, confirming the correctness of our result.

Why Other Options Are Wrong:
Rs 1600 corresponds to the combined share of Sandy and Mandy, not Andy. Rs 1400, Rs 800, and Rs 1200 correspond to different fractions of the total work that do not match Andy actual fraction of 5/13. Only Rs 1000 is consistent with Andy being responsible for 5/13 of the work and the total payment of Rs 2600.

Common Pitfalls:
A common error is to divide the payment equally among workers, ignoring their different contributions. Others may mistakenly use 8/13 instead of 5/13 for Andy, misreading which fraction belongs to whom. Always carefully identify who did which fraction of the total work and check that all fractions add to 1 before computing any payment share.

Final Answer:
Andy share of the payment is Rs 1000.