### Core Concept The problem involves calculating the work rates of two individuals, Renu and Seema, and then combining their efforts under specific conditions to determine the number of days Seema will work. The key formula used is:
Work=Rate×Time ### Step-by-Step Solution
1
Calculate Total Work Hours:
Renu's total work hours:
15 days×4 hours/day=60 hours
Seema's total work hours:
8 days×5 hours/day=40 hours
2
Determine Individual Rates:
Renu's rate:
60 hours1 task=601 per hour
Seema's rate:
40 hours1 task=401 per hour
3
Set Up Working Conditions:
Renu works 2 hours per day.
Seema works double the hours per day as Renu:
2×2=4 hours/day
Let the number of days Seema works be
D. Then, Renu works
2D days.
4
Calculate Total Hours Worked:
Renu's total hours:
2 hours/day×2D days=4D hours
Seema's total hours:
4 hours/day×D days=4D hours
Renu's work:
601×4D=604D=15D