Question

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A can do a work in one day. B can do it in a hour. How much time will they take to do the work together. ​

Answer 1

☞. REQUIRED ANSWER :- Method 1:

1 hr work of A = 1/5

1 hr work of B = 1/10

1 hr work of both = 1/5 + 1/10 = (10+5)/50 = 15/50=3/10

So they together can do this job in = 10/3 hours = 10/3 * 60 min = 200 min

Method 2:(Formula method)

if A can do a job in x days and B can do this job in y days then they together can do this job in = xy/(x+y) = 5*10/(5+10) = 50/15 hours = 10/3 hours

= 10/3 * 60 min = 200 min

Method 3:(LCM method)

let total work = LCM(5,10) = 10 units

1 hr work of A = 10/5 = 2 units and that of B = 10/10 = 1 unit

Hence A & B together this work in = 10/(2+1)=10/3 hours

= 10/3 * 60 min = 200 min

HOPEFULLY IT HELPFUL YOU ☑️☑️☑️

Answer 2

➪ In 6 hours A can do a work

➪ so, in 1 hour A is doing 1/6 of the work . similarly B is doing 1/14 of the work in 1 hour .

➪ they together in 1 hour are doing (1/6+1/14) of the work .

=(7+3)/42 =10/42=5/21 of the work

so, together they will complete the work in 21/5 days =4.2 days