Question

Q Dikshit and Sammit can do a work in 36 days and 24 days respectively. They started the work together but
Sammit left after 3 days before the completion of the work. How much time will be taken to complete the
work?
Ops: A. 13.2 days
B. 17.4 days
C. 11.33 days
D. 16.2 days

Answer 1

Answer:

dikshit - a , sammit- b

Step-by-step explanation:

The required equation is

27/36 + (27- N)/24= 1

So 3/4 + 27/24- N/24= 1

SoN/24= 27/24+ 3/4- 1 = 21/24

So N= 21.

Therefore A- joined -B after 21- days to complete the work.

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Another Method:

In 27- days -B- alone will complete 27/36= 3/4- part of the work.

So the remaining (1–3/4)= 1/4- part of the work was exclusively done by A- alone. He will complete 1/4 of the work in = (1/4)/1/24)= 6- days.

He worked only for 6- days. ie he joined B- after (27- 6)= 21- days.

OK.

+++++++++++++++++++++++++++++

After 21 days, A joined.

Assign X to the number of days B worked alone. Assign total work value as Unit 1.

Output of A per day= 1/24 unit; output of B per day=1/36 unit; work done by B alone = x days*1/36 unit work/day…=X/36 unit. Work remaining = 1-(x/36).

work done by A and B together= (27-X)*(1/24)+ (27-x) *1/36={1-(x/36)}.

solve for x, u get X=21.

Efficiency of A = 1/24 th part of work per day

Efficiency of B = 1/36 th part of work per day

A joined B say after n days

Part of work done by B in n days = n/36 th

The work remained to be done = (1 - n/36)

The combined efficiency of A & B = 1/24 + 1/36 = 5/72 th part of work per day

(1 - n/36)*72/5 = 27 - n

72 - 2n = 135 - 5n

3n = 135 - 72 = 63

n = 21

A joins B after 21 days

please mark my answer as brainliest .