Lemon, Tea and Dates
Read the puzzle
Four lines of picture sums use lemons, cups of tea and dates. Line 1: lemon + lemon + lemon = 30. Line 2: lemon + cup of tea + cup of tea = 20. Line 3: cup of tea + date + date = 9. Line 4: cup of tea + lemon x date = ?. What is the answer to the last line?
What is the answer to the last line?
Remember: multiply before you add.
25
Lemon 10, cup 5, date 2. Multiply first: 5 + 20 = 25.
How to solve it
Step one: find the lemon. Three lemons make 30, so one lemon is 30 / 3 = 10.
Step two: find the cup of tea. Lemon plus two cups is 20, so two cups are 20 - 10 = 10, and one cup is 5.
Step three: find the date. One cup plus two dates is 9, so two dates are 9 - 5 = 4, and one date is 2.
Step four: solve the last line, cup + lemon x date. Multiplication comes before addition, so work out lemon x date first: 10 x 2 = 20. Then add the cup: 5 + 20 = 25.
The usual wrong answer is 30, from working left to right: 5 + 10 = 15, then 15 x 2 = 30. That ignores the order of operations, which says multiply before you add unless brackets say otherwise.
Another slip is misreading the x as a plus, giving 5 + 10 + 2 = 17.
Quick check: put the values back into every line. 10 + 10 + 10 = 30, 10 + 5 + 5 = 20 and 5 + 2 + 2 = 9, so the values are right and the last line is 25.
