other govt exam DRDO CEPTAM Admin & Allied (A&A) 2022 Mock Test Quantitative Aptitude Time and Work Work Efficiency
A can do a work in 20 days and B can do it in 14 days. If they work together for 7 days, then the fraction of the work left is:
1
\({ {3} \over 10}\)
2
\({ {3} \over 20}\)
3
\({ {7} \over 20}\)
4
\({ {7} \over 10}\)