This is an independent topic guide, not the official syllabus. Compare it with the current paper outline and rules published by the examination authority.
01 / UNDERSTANDING
Learning objectives
Cover reciprocal rates, combined work, partial completion and segmented participation. Explain the unit method as an alternative representation of the same rate relationship, not a separate rule.
02 / UNDERSTANDING
The concept in context
If a person completes a job in a stated number of days at a constant rate, one day’s work is the reciprocal of that time. Add compatible rates for people working together, then divide the remaining work by the combined rate. Completion times themselves cannot normally be added to obtain joint completion time.
03 / UNDERSTANDING
A worked learning case
Original educational case. A can finish an original document-checking task in six days and B in three days, assuming constant independent rates. Choose six work units: A handles one unit daily and B two. Together they finish three units daily, so the six-unit task takes two days. Adding six and three would describe neither their joint rate nor their completion time.
ORIGINAL EDUCATIONAL PRACTICE
Try it before you check.
Original practice: A takes 12 days and B takes 6 days for one job. How long together at constant additive rates?
Show the answer and reasoning
4 days.
A’s daily rate is 1/12 and B’s is 1/6 of the job. Their combined rate is 3/12, or one quarter per day. One full job therefore takes four days. The answer is shorter than either individual time, which also provides a useful reasonableness check under the stated additive-rate assumption.
Two traps to watch for.
- Adding individual completion times instead of rates.
- Ignoring a change in workforce during a later time segment.
YOUR TOPIC-SPECIFIC LEARNING MAP
Your revision map
Choose one job or convenient work units.
Write each contribution per day.
Check the remaining work after every segment.
Explain the idea, apply it to a new situation, then check what changed in your reasoning.
BANKERS TUTORIAL · SOURCE NOTES
Keep the source alongside your notes.
Official links provide subject context and authoritative reference material. This guide’s explanation, scenario and question are original Bankers Tutorial learning content.
- sbi.bank.in https://sbi.bank.in/web/careers/current-openings
- sbi.bank.in https://sbi.bank.in/webfiles/uploads/files_2627/09/SBI_JA-Customer_Support_Sales-IH_Pre-2026-27_Eng.pdf
For SBI preparation, check the current official notice before relying on changing dates, rules or examination requirements.
