The summation indicates the sum from n = 1 to n = 3 of the expression 2(n+5).
2 (n+5) = 2n + 10
2n + 10 denotes an Arithmetic Series, with a common difference of two and first term as 12.
For n =1, it equals 12
For n = 2, it equals 14
For n = 3, it equals 16
So the sum from n=1 to n=3 will be 12 + 14 + 16 = 42
Sum of an Arithmetic Series can also be written as:

Using the value of a₁ and d, we can simplify the expression as:

This expression is equivalent to the given expression and will yield the same result.
For n=3, we get the sum as:
S₃ = 3(11+3) = 42
If you search it up on google the answer pops up!!1
Let price of the Caleb's groceries was $x.
Given that tax rate is 2.5% or 0.025
Then sales tax is given by product of 0.025 and x.
which is 0.025x.
Given that tax paid is $1.60 so both must be equal

divide both side by 0.025


Hence final answer is $64.