Let's assume number of males 5 * a = 5a
number of females 7 * a = 7a
As per question total population is 396
therefore 5a + 7a = 396
12a = 396
a = 396÷12
a = 33
Let's place the value of in the equation
5a + 7a = 396
5*33 + 7*33 = 396
165 +231 = 396
so 165 of 396 are males
