Let:
T = Total number of boxes in the shipment
F = Number of fragile boxes
NF = Number of non-fragile boxes (T=F+NF)
FE = Number of fragile boxes containing electronics
NFE = Number of non-fragile boxes containing electronics
E = Total number of boxes containing electronics (E=FE+NFE)
The question is: Is FE>0.5F?
lets check Statement (1): Two-thirds of the boxes in the shipment are fragile.
This translates to F=(2/3)T.
From this, we also know NF=T−F=T−(2/3)T=(1/3)T.
This statement tells us the proportion of fragile boxes in the shipment but gives no information about whether these boxes contain electronics.
Therefore, Statement (1) alone is not sufficient.
lets check Statement (2): Four-fifths of the boxes in the shipment contain electronics.
This translates to E=(4/5)T.
This statement tells us the total proportion of boxes with electronics but gives no information about how these electronics are distributed between fragile and non-fragile boxes.
Therefore, Statement (2) alone is not sufficient.
lets combine Statements (1) and (2):
From (1): F=(2/3)T
From (2): E=(4/5)T
We want to know if FE>0.5F.
Substitute F=(2/3)T into the inequality:
Is FE>0.5×(2/3)T?
Is FE>(1/3)T?
We know that FE is the number of fragile boxes that contain electronics.
We also know that E=FE+NFE.
The total number of boxes with electronics is E=(4/5)T.
The maximum possible value for FE is F (if all fragile boxes contain electronics).
The minimum possible value for FE is E−NF (if all non-fragile boxes contain electronics first, then the remaining electronics must be in fragile boxes).
Let's use the proportions.
Total boxes = T
Fragile boxes F= 2/3 T
Non-fragile boxes NF= 1/3 T
Total electronics boxes E= 4/5T
We want to know if the proportion of fragile boxes that contain electronics, relative to the total fragile boxes, is greater than 0.5.
Let's find the possible range for FE.
We know that 0≤FE≤F.
And we know that 0≤NFE≤NF.
Also, FE=E−NFE.
So, FE= 4/5T−NFE.
Since NFE can be at most NF=1/3T
Minimum FE= 4/5T−1/3T =7/15T.
So, FE≥7/15T
Since FE can be at most F=2/3T
Maximum FE=2/3T
So, we know that 7/15T≤FE≤2/3T
Now let's check the condition FE>0.5F.
We know F=2/3T
So, 0.5F=0.5×2/3T=1/3T
The question is: Is FE>1/3T?
We found that the minimum possible value for FE is 7/15T.
Since 7/15T>5/15T.
Since the minimum possible number of fragile boxes containing electronics (7/15T) is already greater than half the total number of fragile boxes (1/3T), it means that in all possible scenarios consistent with both statements, more than half of the fragile boxes must contain electronics.
Therefore, both statements combined are sufficient.