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सी.आई.एस.सी.ई.आईसीएसई ICSE Class 7

A, B and C Can Do a Piece of Work in 12, 15 and 20 Days Respectively. How Long Will They Take to Do It Working Together ? - Mathematics

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प्रश्न

A, B and C can do a piece of work in 12, 15 and 20 days respectively. How long will they take to do it working together?

योग
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उत्तर

A can do a piece of work in 12 days

B can do the same work in 15 days

C can do the same work in 20 days

∴ A's 1 day's work = `1/12`

B's 1 day's work = `1/15`

C's 1 day's work = `1/20`

∴ (A + B + C)'s together 1 day's work

`= 1/12 + 1/15 + 1/20`

`= (5 + 4 + 3)/60 = 12/60 = 1/5`

∴ they can do the work in 5 days.

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अध्याय 7: Unitary Method (Including Time and Work) - Exercise 7 (C)

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सेलिना Concise Mathematics [English] Class 7 ICSE
अध्याय 7 Unitary Method (Including Time and Work)
Exercise 7 (C) | Q 5

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