Question 11 & 12
Question 11: 1 millimetre thick paper if folded 50 times then find the thickness of the fold.
FPSC AD IB 2018
Solution:
We know
and
or
or
So, we can other way say that;
so, 1 millimeter is equal to 0.000001 kilometer
or we can say that single paper is 0.000001 km thick
If we fold this paper one time then there will be two layers of papers;
One time folding
times of 0.000001
Second time folding, (there will be four layers of papers)
Third time folding ( there will be 8 layers of papers)
Fourth time folding (there will be 16 layers of paper)
,,,,,,,,,,,,,,,,,,,,,, so on ,,,,,,,,,,,,,,,,,,>,,,,,,,,,,,,,,,,,so on,,,,,,,,,,,,,,,,,,,>,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,>,,,,,,,,, so on ,,,,,,,,,,,,,,,,,,,,,,,,>,,,,,,,,,,,,,,,,,,,,,,,,,,,, till
Fiftieth time folding
Now let’s evaluate the term =
So, if a paper of 1 mm thickness is folded 50 times then it’s thickness will be equal to 11258999906.842624 kilometers
Or 112 billion kms approximately
Question 12: Total age of 3 men if added is 80 years. What was the sum three years ago?
FPSC AD IB 2018
Solution:
Let there be three persons A, B and C and their ages at present be x, y and z, Then according to the given condition;
Three years ago the ages of A, B and C was x-3, y-3 and z-3 respectively. Now the sum of ages three years ago will be;
Now let us simplify this term;
Sum of ages three years ago =
Putting value of x+y+z from eq (1)
So sum of ages three years ago is 71