text: Let g = # of girls in the math club last year\n(which is what we're looking for)\nand b = # of boys in the math club last year\n\ng + b = 75, or b = 75 - g\n1.25g + 1.4b = 99\n\nTherefore,\n1.25g + 1.4(75 - g) = 99\n1.25g + 105 - 1.4g = 99\n105 - 0.15g = 99\n-0.15g = -6\ng = 40  (which means b = 35)\n\nChecking my work:\nA growth of 25% for girls would mean the number of girls went from 40 to 1.25*40, which is 50.\nA growth of 40% for boys would mean the number of boys went from 35 to 1.4*35, which is 49.\nAnd 50 + 49 = 99.