balboa wrote:
The box contains 10 tablets of medicine A and 15 tablets of medicine B. N tablets are taken from the box at random. What is the least possible N that ensures that at least two tablets of each kind are among the extracted?
(A) 12
(B) 15
(C) 17
(D) 19
(E) 21
Source: GMAT Club Tests - hardest GMAT questions
I am trying to decide between a & c. Possible explanations?
(A) 12
(B) 15
(C) 17
(D) 19
(E) 21
[Reveal] Spoiler: OA
C
Source: GMAT Club Tests - hardest GMAT questions
I am trying to decide between a & c. Possible explanations?
BELOW IS REVISED VERSION OF THIS QUESTION:
A box contains 10 tablets of medicine A and 15 tablets of medicine B. What is the least number of tablets that should be taken from the box to ensure that at least two tablets of each kind are among the extracted?
A. 12
B. 15
C. 17
D. 19
E. 21
The worst case scenario will be if we remove all 15 tablets of medicine B first. The next 2 tablets we remove have to be of medicine A, so to guarantee that at least two tablets of each kind will be taken we should remove minimum of 15+2=17 tablets.
Answer: C.