Note that the number of people, x, is not an amount that we need to determine the answer to the question asked.

For Bunto, we can make an equation so that g+b = $6.20 (where g = price of one gyro for each member of the group and b = price of a beer for each member of the group) and an equation 4g+b=$17.60 for Kristi.

Now, we must subtract the first equation from the second, to get 3g=$11.40.

=> 4g+b=$17.60
- (g+b = $6.20)
   3g = 11.40

Dividing both sides of this new equation by 3, we get:

=> g=^11.40/₃ = $3.80.

To get the total that Kristi spent on her 4 gyros, we simply multiply 4(3.80)=$15.20. This is our answer.

As a check, we can find the price of a beer by taking $6.20-$3.80=$2.40 and then taking $15.20+$2.40 to make sure we get $17.60 for Kristie's total spending.

The correct answer is A.