🌳 Trees in a row — count the gaps, not the trees

A closer look at one question · SMC 2026 mock, Question 19 (bank id B4)

A farmer planted trees in a straight row, equally spaced. The distance between the 2nd tree and the 5th tree was 2340 m. What was the distance between the 1st tree and the 10th tree?

1 Count the SPACES between trees, not the trees

🌳1

🌳2

🌳3

🌳4

🌳5

⋯

🌳10

From the 2nd tree to the 5th tree there are 5 − 2 = 3 gaps between them, not 4 trees' worth.

2 Find the length of ONE gap

3 gaps

780 m780 m780 m

2340 ÷ 3 = 780 m per gap.

3 The 1st to the 10th tree spans 9 gaps

10 − 1 = 9 gaps, so the distance is 9 × 780 = 7020 m.

7020 m

The trap: counting TREES instead of GAPS — using 4 and 10 instead of 3 and 9. Mark the gaps on a quick sketch before dividing.