English, asked by mahi1413, 1 year ago

A clock goes fast by one minute during the first

hour, by two minutes at the end of the second

hour, by 4 minutes at the end of 3 hour, by eight

minutes by the end of 4th hour and so on. At the

end of which hour will it be fast by just over

sixty minutes ?

(a) Fifth (b) Sixth

(c) Seventh (d) Eighth
plz explain

Answers

Answered by delroy

here's your answer --

( option c ) seventh hour

hope it helps !!

have a nice day !!

mahi1413: plz xpln

delroy: every hour the time increased is multiplied by 2. like in 1st hour it is just 1 min, in 2nd hour it is 1×2=2, in 3rd hour it is 2×2=4, similarly in the 4th hour it is 4×2=8

delroy: now the options are-- 5th, 6th, 7th and 8th hours

delroy: in 5th hour it will be 8×2=16

delroy: in 6th hour it will be 16×2=32

delroy: in 7th hour it will be 32×2=64

delroy: in the 8 hour it will be 64×2=128

delroy: now, it is asked that when the time will be just over 60 minutes, which is obtained after the 7 hour ( 64 minutes )

delroy: so the answer is 7th hour

mahi1413: tqu so much

Answered by Abhijeet1589

The correct answer is option (c) seventh hour.

GIVEN

Minutes of the clock going fast at the First hour = 1 min

Minutes of the clock going fast at the second hour = 2

Minutes of the clock going fast at the third hour = 4mins

Minutes of the clock going fast at the 4th hour = 8 mins.

TO FIND

At the end of which hour will the clock fast by just over 60 minutes?

SOLUTION

We can simply solve the above problem as follows-

By the data given, we can observe that the clock is going faster 2 times the minutes in the previous hour.

So,

Minutes of the clock going faster at the end of the 5th hour = 2 × 8 = 16 minutes.

Minutes of the clock going faster at the end of the 6th hour = 2×16 = 32 minutes.

Minutes of the clock going faster at the end of the 7th hour = 2×32 = 64 minutes.

Since,

64>60

So,

At the end of the Seventh hour, the clock will be faster by just over 60 minutes.

#spj2

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