4 sets of uniforms were issued to each combat soldier and 3 sets of uniforms were issued to each non-combat soldier in an army camp. The ratio of the number of soldiers in the camp to the number of uniforms issued was 7:25. What fraction of the soldiers in the army camp were combat soldiers?
Q. 4 sets of uniforms were issued to each combat soldier and 3 sets of uniforms were issued to each non-combat soldier in an army camp. The ratio of the number of soldiers in the camp to the number of uniforms issued was 7:25. What fraction of the soldiers in the army camp were combat soldiers?
Identify uniforms per soldier type: Identify the total number of uniforms issued per soldier type. Combat soldiers: 4 uniforms each, Non-combat soldiers: 3 uniforms each.
Define variables and total: Let x be the number of combat soldiers and y be the number of non-combat soldiers. The total number of soldiers is x+y. The total number of uniforms issued is 4x+3y.
Set up ratio equation: Given the ratio of the number of soldiers to the number of uniforms is 7:25. Set up the equation (x+y)/(4x+3y)=7/25.
Cross-multiply for x and y: Cross-multiply to solve for x and y: 25(x+y)=7(4x+3y). Simplify to 25x+25y=28x+21y.
Rearrange equation: Rearrange the equation: 25x+25y−28x−21y=0, which simplifies to −3x+4y=0.
Solve for y in terms of x: Solve for y in terms of x: 4y=3x, y=43x.
Substitute back into total: Substitute y=43x back into the total number of soldiers: x+43x=7k (where k is a scaling factor). Simplify to 47x=7k.
Find x and y values: Solve for x: x=4k. Then, y=3k.
Calculate fraction of combat soldiers: Find the fraction of combat soldiers: x/(x+y)=4k/(4k+3k)=4/7.