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SSC Selection Post 2022 PYQ — Question 67

SSC Selection Post - Matriculation Level - 05 Aug 2022 - Shift 1 • Quantitative Aptitude • Q67

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A can do three-seventh of a work in 15 days and B can do two-fifth of the same work in 14 days. If A and B work together, then how long (in days) will they take to complete the work?

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Correct answer: D

Explanation

The correct answer is Option 4 i.e. 171217{{1} \over 2}.

Let the total work be 'x',

Amount of work done by A in one day = (3x/7) × 1/15 = x/35 units

Amount of work done by B in one day = (2x/5) × 1/14 = x/35 units

Amount of work done by A and B both = x/35 + x/35 = 2x/35

Since x is total work, then,

Time taken to do total work done by A and B both = x2x35=352=1712\frac{x}{\frac{2x}{35}} = \frac{35}{2} = 17\frac{1}{2}  days