Q. The ratio boys : girls in a park is 1:4. 65 girls leave and the ratio becomes 4:3.Work out how many boys there are in the park.□ boys
Initial Ratio Explanation: Initial ratio of boys to girls is 1:4. This means for every boy, there are 4 girls. Let's denote the number of boys as b and the number of girls as 4b.
New Ratio Calculation: After 65 girls leave, the ratio changes to 4:3. The new number of girls is 4b−65. The new ratio can be expressed as 4b−65b=34.
Equation Simplification: To find b, we solve the equation 4b−65b=34. Cross-multiplying gives 3b=4(4b−65).
Solving for b: Simplifying the equation: 3b=16b−260. Then, 260=16b−3b, 260=13b.
Final Number of Boys: Solving for b, we get b=13260, b=20. So, there are 20 boys in the park.
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