The average length of the first three fingers is 3 inches and the average length of the other 2 fingers i.e. thumb and the index finger is 2.8 inches if the length of the index fingers is 3 inches then the length of the thumb is:

Options

A. 2 inches
B. 2.6 inches
C. 3 inches
D. none of these

Answer

To find the length of the thumb, we can follow these steps:

### Step 1: Calculate the total length of the first three fingers.
The average length of the first three fingers is given as 3 inches. To find the total length, we multiply the average by the number of fingers.

\[ \text{Total length of first three fingers} = \text{Average} \times \text{Number of fingers} = 3 \, \text{inches} \times 3 = 9 \, \text{inches} \]

### Step 2: Calculate the total length of the thumb and index finger.
The average length of the thumb and index finger is given as 2.8 inches. To find the total length of these two fingers, we again multiply the average by the number of fingers.

\[ \text{Total length of thumb and index finger} = \text{Average} \times \text{Number of fingers} = 2.8 \, \text{inches} \times 2 = 5.6 \, \text{inches} \]

### Step 3: Subtract the length of the index finger from the total length of the thumb and index finger.
We know that the length of the index finger is 3 inches. To find the length of the thumb, we subtract the length of the index finger from the total length of the thumb and index finger.

\[ \text{Length of thumb} = \text{Total length of thumb and index finger} - \text{Length of index finger} = 5.6 \, \text{inches} - 3 \, \text{inches} = 2.6 \, \text{inches} \]

### Conclusion:
The length of the thumb is **2.6 inches**.

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