Two friends, Gauri and Naina, are cowherds. One day, they pass each other on the road with their cows. Gauri says to Naina, 'You have twice as many cows as I do'. Naina says, 'That's true, but if I gave you three of my cows, we would each have the same number of cows'. How many cows do Gauri and Naina have?
Given: Let g = Gauri's cows Let n = Naina's cows
Equations: From 'Naina has twice as many': n = 2g From 'if Naina gave 3 to Gauri, they would be equal': n - 3 = g + 3
Substitution: 2g - 3 = g + 3
Solving: 2g - g = 3 + 3 g = 6
Finding n: n = 2g = 2(6) = 12
Answer: Gauri has 6 cows and Naina has 12 cows.
Explanation
Using algebra: Let g = Gauri's cows, n = Naina's cows. From first statement: n = 2g. From second statement: if Naina gives 3 cows to Gauri, they have equal numbers, so n - 3 = g + 3. Substituting n = 2g: 2g - 3 = g + 3, giving g = 6 and n = 12.
Solution Steps
Step 1: Let g = Gauri's cows, n = Naina's cows
Step 2: From 'Naina has twice as many': n = 2g
Step 3: From 'if Naina gave 3 to Gauri, they would be equal': n - 3 = g + 3
Step 4: Substitute: 2g - 3 = g + 3
Step 5: Solve: g = 6
Step 6: Therefore n = 12