JAMB Geography 2022 Paper

Concept:To find the ground distance, multiply the map distance by the denominator of the scale, then convert centimetres to kilometres.Explanation:The map distance between the two towns is $10\text{ cm}$.For map (a), scale is $1:100{,}000$.This means $1\text{ cm}$ on the map represents $100{,}000\text{ cm}$ on the ground.So ground distance for (a) is $10 \times 100{,}000 = 1{,}000{,}000\text{ cm}$.Convert to kilometres: $1{,}000{,}000 \div 100{,}000 = 10\text{ km}$.For map (b), scale is $1:400{,}000$.Thus ground distance for (b) is $10 \times 400{,}000 = 4{,}000{,}000\text{ cm}$.Convert to kilometres: $4{,}000{,}000 \div 100{,}000 = 40\text{ km}$.Answer:The ground distances are $10\text{ km}$ and $40\text{ km}$. Therefore, the correct option is A.