Question

a cistern in normally filled in 8 hr but takes 2 hr longer to fill because of a leak in its bottom. If the cistern is full, the leak will empty it in

Answer 1

5 hrs will be taken to empty the cistern as the total time taken will be 10 hrs and then divide it by 2

Answer 2

Answer:

Step-by-step explanation:

A = 8 hrs

(A-B) = 8+2Hrs more =10 hrs

L.C.M of (8,10)=40 {#every time this will let the total units.}

A = 40/8 = 5 units,

(A-B) = 40/10= 4 units,

@ X (A-B) = 40

@ X (5-4) = 40

@X = 40/1 = 40HRS - - - - - << ANSWER

#Remember unit is the workdone/hour

CROSSCHECK ->

A can fill it in 8 hour ,

B can empty it in 40 hour ,

both (A- B) together takes time to fill ?  # '-B' because its a leakage

now , L.C.M of 8 & 40 is 40

A= 40/8 = 5 unit

B= 40/40 = -(1 unit)

now

X(A-B) = 40 unit     #bcz L.C.M is 40

X(5unit- 1unit) = 40 unit

X = 40Unit /(4 Unit)

X = 10 HOUR