A snail covered 3mm in the frst sec and 4 mm each in each successive sec,for a certain number of sec.However if it had covered 1mm in the 1 st sec and 8 mm more in each successive sec for some secs, then the difference between the length of the path it would have covered during the same time and the actual path that it actually took would have been more than 6 mm but less than 30 mm.find the time for which the snail moved? A)4sec B)5sec C)8sec D)10sec
Answers
Answer:
The correct option is A) 4 sec
Step-by-step explanation:
Consider the provided information.
A snail covered 3mm in the frst sec and 4 mm each in each successive sec,for a certain number of sec.
The pattern of movement is:
3+7+11+15+19+23
If it had covered 1mm in the 1 st sec and 8 mm more in each successive sec for some secs,
The pattern of movement is:
1+9+17+25+33+41
The difference in the net movement between second and the first pattern is more than 6 mm and less than 30mm can be calculated as:
For 2 second:
In 2 seconds 1st pattern is 3+7=9
In 2 seconds 2nd pattern is 1+9=10
The difference is 1 mm.
Similarly.
In 3 seconds 1st pattern is 3+7+11=21
In 3 seconds 2nd pattern is 1+9+17=27
The difference is 6 mm. Since, distance should be more than 6. So, ignore this.
In 4 seconds 1st pattern= 3+7+11+15=36
In 4 seconds 2nd pattern= 1+9+17+25=52
The difference is 16 mm. Since, distance is in between more than 6 and less than 30, thus the required sec is 4.
The correct option is A) 4 sec.