Question

Please solve this!!
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Answer 1

Answer:

20minutes

Step-by-step explanation:

A fill in 1min = 1/28 part

B fill in 1 min = 1/21 part

A and B together fill in 1 min = (1/28+1/21) = 1/12 part

1/12 part fill in 1 min

1/2 part fill in 1×12×1/2 = 6 min

Remaining part = 1-1/2 = 1/2 part

A fill 1/28 part in 1 min

A fill 1/2 part in 1×28×1/2 = 14 min

Total time taken = 6+14 = 20 minutes