Question

math

Reena climbs up 5 stairs every second and then climbs down 2 stairs over the next second. How many seconds will she take to climb 60 stairs? ​

Answer 1

Answer:

39 seconds.

Step-by-step explanation:

Given:

Reena climbs up 5 stairs every second and then climbs down the next second.

So, she must take 2 seconds to climb up 3 stairs.

If, 3 stairs = 2 seconds

then, 60 stairs = $\frac{2}{3}×60$ seconds

For 60 stairs, $\bf{40\:seconds}$

As he climbs up 60 stairs he doesn't need to climb down, so, he takes one second less in climbing up than the actual time, i.e, $\bf{40-1=39seconds}$

Answer 2

Given data:

Reena climbs up 5 stairs Every second and then climb down 2 stairs over the next second.

To find:

The total time taken by Reena to climb 60 stairs.

Solution:

As for every second she climbs 5 stairs and in the next second she climbs down 2 stairs,

Total stairs she climbs in 2 seconds = 5 - 2 = 3 stairs.

Total number of steps climbed by Reena = 60 stairs  

Therefore, time take by Reena to climb 60 stairs

                                  = (60/3)(2)    [As she takes 2 seconds to climb 3 stairs]

                                  = 40 seconds

But, at 39th second, we know that she climbs 5 stairs making it 62, which means, she'll be out of the complete 60 stairs making it no need to climb down further.

So, Time taken by Reena to climb 60 stairs = 40 – 1 = 39 seconds

Therefore, the total minimum time taken by Reena to climb 60 stairs is 39 seconds.

Learn more:

Three taps A, B and C can fill a tank in 10 minutes, 15 minutes and 20 minutes respectively. If the taps were shut off after 5 minutes, what is the volume of water that overflowed in %?​

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Amit climbs up 5 stairs in one second.He then climb down 3 stairs in next one second.How many seconds will he take to climb 62 stairs ?

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