Rankle #112 answer: energy content per unit mass (lowest to highest)

The answer

Rank by energy content per unit mass (lowest to highest)

1. 1Wood (dry)15 MJ/kg
2. 2Coal (anthracite)30 MJ/kg
3. 3Petrol46 MJ/kg
4. 4Hydrogen120 MJ/kg

Why this order

Ranked lowest to highest, Wood (dry) (15 MJ/kg) goes at the top and Hydrogen (120 MJ/kg) at the bottom.

The closest call is Wood (dry) (15 MJ/kg) against Coal (anthracite) (30 MJ/kg), 15 apart. That is the swap most likely to cost a point.

The biggest gap is between Petrol and Hydrogen, 74 apart, so that boundary should be the easiest part of the order to get right.

These are the figures the game reveals after you submit. They are rounded; only the order is scored.

Difficulty: medium, judged by how close the tightest pair is.

How it was scored

right slot, one place out, two or more out. The score is how many items sit in the right slot, and only 4/4 is a win. Full rules on the how to play page.