CAT 1994 — QA Question 19
Answer the next 2 questions based on the following information:
If
md(x) = x ,
mn(x,y) = minimum of x and y and
Ma(a,b,c,...) = maximum of a,b,c…
Along a road lie an odd number of stones placed at intervals of 10m. These stones have to be assembled around the middle stone. A person can carry only one stone at a time. A man carried out the job starting with the stone in the middle, carrying stones in succession, thereby covering a distance of 4.8 km. Then the number of stones is
Answer & solution
- A
35
- B
15
- C
29
31
As the person covers 4.8 km, he covers 2.4 kms on one side and 2.4 kms on other side.
Let the number of stones be ‘n’ on either side of the road excluding the middle stone.
So total distance covered by him on one side = 20 + 40 + 60 + … + 20n
∴ 2400 = (2 × 20 + (n - 1)20) = 10n (n + 1)
(Here n is the number of stones)
After solving, we get n = 15
∴ Total number of stones = 15 + 15 + 1 = 31
Hence, option (d).