Amit and Sumit can separately finish the work in 15 days and 25 days respectively. They worked together and Amit left the work, So Sumit complete the remaining work in 5 days. Find after how many days Amit left the work?a)b)c)6daysd)Correct answer is option 'B'. Can you explain this answer?

Question

Answer

GIVEN:

Amit can do a work in 15 days.

Sumit can do a work in 25 days.

FORMULA USED:

Amit one day work × working days + Sumit one day work × working days = 1

CALCULATION:

Let Amit left after x days.

Sumit worked for (x + 5) days.

⇒ 1/15 × x + 1/25 (x + 5) = 1

⇒ x/15 + x/25 + 1/5 = 1

⇒ (5x + 3x)/75 = 4/5

⇒ 8x/75 = 4/5

Alternate method:

Let total work = LCM of (15, 25) = 75

So, Amit’s 1 day work = 5 & Q’s 1 day work =3

So Sumit’s 5 days work in last = 3 × 5 = 15

So remaining work = 75 - 15 = 60

So this 60 units of work is completed by both in = 60/(5 + 3) = 60/8 =

Answer

GIVEN:

Amit can do a work in 15 days.

Sumit can do a work in 25 days.

FORMULA USED:

Amit one day work × working days + Sumit one day work × working days = 1

CALCULATION:

Let Amit left after x days.

Sumit worked for (x + 5) days.

⇒ 1/15 × x + 1/25 (x + 5) = 1

⇒ x/15 + x/25 + 1/5 = 1

⇒ (5x + 3x)/75 = 4/5

⇒ 8x/75 = 4/5

Alternate method:

Let total work = LCM of (15, 25) = 75

So, Amit’s 1 day work = 5 & Q’s 1 day work =3

So Sumit’s 5 days work in last = 3 × 5 = 15

So remaining work = 75 - 15 = 60

So this 60 units of work is completed by both in = 60/(5 + 3) = 60/8 =

Answer

GIVEN:

Amit can do a work in 15 days.

Sumit can do a work in 25 days.

FORMULA USED:

Amit one day work × working days + Sumit one day work × working days = 1

CALCULATION:

Let Amit left after x days.

Sumit worked for (x + 5) days.

⇒ 1/15 × x + 1/25 (x + 5) = 1

⇒ x/15 + x/25 + 1/5 = 1

⇒ (5x + 3x)/75 = 4/5

⇒ 8x/75 = 4/5

Alternate method:

Let total work = LCM of (15, 25) = 75

So, Amit’s 1 day work = 5 & Q’s 1 day work =3

So Sumit’s 5 days work in last = 3 × 5 = 15

So remaining work = 75 - 15 = 60

So this 60 units of work is completed by both in = 60/(5 + 3) = 60/8 =

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