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90 Men Can Complete a Work in 24 Days Working 8 Hours a Day. How Many Men Are Required to Complete the Same Work in 18 Days Working 7 1/2 Hours a Day? - Mathematics

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Question

90 men can complete a work in 24 days working 8 hours a day. How many men are required to complete the same work in 18 days working `7 1/2` hours a day?

Sum
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Solution

In 24 days, working 8 hours a day, work can be completed by = 90 men

In 1 day, working 8 hours a day, work can be completed by = 90 × 24 men

In 18 days, working 8 hours a day, work can be completed by =`(90xx24)/18` men

In 18 days, working 1 hour a day, work can be completed by = `(90xx24)/18xx8` men

In 18 days, working `7 1/2` i.e. `15/2` hours a day, work can be completed by =`(90xx24xx8)/18xx2/15` men

`=(90xx24xx8xx2)/(18xx15)=(1xx24xx8xx2)/3` = 128 men

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Chapter 10: Direct and Inverse Variations - Exercise 10 (D) [Page 129]

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Selina Concise Mathematics [English] Class 8 ICSE
Chapter 10 Direct and Inverse Variations
Exercise 10 (D) | Q 7 | Page 129

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