Each stamp cost 20, 25 or 30 cents
Total money spent on stamps = 20x + 25y + 30z
Target question => What is the number of 25 cent stamps? i.e find y
Given that she bought at least one of each denomination
Total money is at least 20 + 25 + 30 = 75 cents
Statement 1 => She spent a total of $1.45 for stamps i.e 145 cents
Possible variation in money spent are:
- (20*2) + (25*3 ) + (30*1) = 145 and y = 3
- (20*3) + (25*1) + (30*2) = 145 and y = 1
These 2 possible scenario yield two different value of y. Hence, statement 1 is NOT SUFFICIENT
Statement 2 => She bought exactly 6 stamps
This statement does not give any information about the quality of each stamp because lots of possible variations and ways of arranging 3 different stamps into 6 places i.e 2,2,2; 2,1,3; 1,2,3; so the exact value of y cannot be determined. Statement 2 is NOT SUFFICIENT
Combining both statements together =>
According to the information available in the two statements, the possible scenarios are (20*2) + (25*3) + (30*1) = 145 and (20*3) + (25*1) + (30*2) = 145 and y = 1
The possible scenarios yield different value of y. Hence, both statements together ARE NOT SUFFICIENT
Answer = E
