Question

Vini travels by monorail to work. She has to use escalator to reach the platform, It takes her 21.0 seconds to reach the top of the escalator if she runs 8 steps. If she runs 13 steps it takes only 13.5 seconds. Select the number of seconds that she would require to reach the top of escalator if she decides not to run any step. (1) 22 (2) 33 (3) 27 (4) 22.2 ​

Answer 1

Answer:

33

Step-by-step explanation:

When she went 8 steps it took 21 sec when she increased the steps by 5 it took here 7.5 seconds less thats 1.5 sec less per step that means that by not running any steps it would take 8×1.5 sec longer

8×1.5=12

now take that number 12 and add it to the 21 sec it took her with running =33

Answer 2

The number of seconds Vini would require to reach the top of the escalator if she decides not to run any step is 33 (Option 2)

Given

Time in seconds Vini takes to reach the top of the escalator when she runs 8 steps = 21 seconds

Time in seconds Vini takes to reach the top of the escalator when she runs 13 steps = 13.5

To Find

Time in seconds Vini takes to reach the top of the escalator if she does not run any step

Solution

The difference in time in seconds when Vini runs 13 steps versus 8 steps to reach the top of the escalator = 7.5 seconds

This means that Vini took 7.5 seconds less to reach the top of the escalator when she ran an additional 5 steps

That also means for each step Vini ran the time taken was reduced by  7.5 ÷ 5 = 1.5 seconds

So, when she ran 8 steps she saved 8 × 1.5 = 12 seconds

Hence, the total time in seconds she would have taken if she had not run those 8 steps = 21 + 12 = 33 seconds.

Hence, the number of seconds Vini would require to reach the top of the escalator if she decides not to run any step is 33 seconds (Option 2)