LET function for named calculations in Excel - Practice Problems & Coding Challenges

Challenge - 5 Problems

📊 Formula Result

intermediate

Output of LET function with simple named variables

What is the output of this formula in Excel?

=LET(x, 5, y, 10, x + y)

Excel

=LET(x, 5, y, 10, x + y)

A 510

B 15

C 5

D 10

💡 Hint

Remember LET assigns names to values and then uses them in the last expression.

The LET function assigns x=5 and y=10, then returns x + y = 15.

❓ Function Choice

intermediate

Choose the correct LET formula to calculate area of a rectangle

You want to calculate the area of a rectangle with length 8 and width 3 using LET. Which formula is correct?

A =LET(length = 8, width = 3, length * width)

B =LET(8, length, 3, width, length * width)

C =LET(length, 8, width, 3, length * width)

D =LET(length, 8, width, 3, length + width)

💡 Hint

LET syntax uses pairs: name, value, then final expression.

Option C correctly assigns length=8 and width=3, then multiplies them for area.

📊 Formula Result

advanced

Result of nested LET with repeated names

What is the result of this formula?

=LET(x, 2, y, LET(x, 5, x + 3), x + y)

Excel

=LET(x, 2, y, LET(x, 5, x + 3), x + y)

A 10

B 13

C 7

D 5

💡 Hint

Inner LET shadows outer x only inside its scope.

Inner LET sets x=5, so y = 5 + 3 = 8. Outer x=2. Result is 2 + 8 = 10.

🎯 Scenario

advanced

Using LET to simplify a complex formula

You have a formula:

=((A1 + B1) * (A1 + B1)) / (A1 + B1)

How can you rewrite it using LET to avoid repeating (A1 + B1)?

A =LET(sum, A1 + B1, (sum * sum) / sum)

B =LET(sum, A1 + B1, sum * sum / (A1 + B1))

C =LET(A1, A1, B1, B1, (A1 + B1) * (A1 + B1) / (A1 + B1))

D =LET(sum, A1 + B1, sum + sum / sum)

💡 Hint

Assign (A1 + B1) to a name and use it in the formula.

Option A assigns sum = A1 + B1 once, then uses it twice, simplifying the formula.

❓ data_analysis

expert

Calculate weighted average using LET

You have scores in cells A1:A3 and weights in B1:B3. Which LET formula correctly calculates the weighted average?

A =LET(totalWeight, SUM(A1:A3), weightedSum, SUMPRODUCT(A1:A3, B1:B3), weightedSum / totalWeight)

B =LET(weightedSum, SUMPRODUCT(A1:A3, B1:B3), weightedSum / SUM(B1:B3))

C =LET(totalWeight, SUM(B1:B3), weightedSum, SUM(A1:A3 * B1:B3), weightedSum / totalWeight)

D =LET(totalWeight, SUM(B1:B3), weightedSum, SUMPRODUCT(A1:A3, B1:B3), weightedSum / totalWeight)

💡 Hint

Weighted average = sum of (score * weight) divided by sum of weights.

Option D correctly sums weights and weighted scores separately, then divides.