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SSC CGL 2023 PYQ — Question 58

SSC CGL - 21 July 2023 - Shift 3 • Quantitative Aptitude • Q58

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Richa, Rita and Reena can independently complete a work in 8 hours, 12 hours and 24 hours, respectively. If they work together, how much time will they take to complete that work?

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Correct answer: A

Explanation

The correct answer is option 1 i.e. 4 hours.

Richa can complete the work in = 8 hours

so her work rate is = 1/8​ per hour.

Rita can complete the work in 12 hours

so her work rate is = 1/12​  per hour.

Reena can complete the work in 24 hours

so her work rate is = 1/24​  per hour.

Combined work rate = 1/8 + 1/12 + 1/24 = 3+2+124\frac{3+2+1}{24}  = 624\frac{6}{24} = 14\frac{1}{4}

Richa Rita and Reena can complete the work in = 4 hours