Answer:
29 attended in all
Explanation:
let a represent the number of adults and c the number of children, then
15a + 9c = 327 → (1)
given there were 7 more children than adults, then
c = a + 7 → (2)
substitute c = a + 7 into (1)
15a + 9(a + 7) = 327 ← distribute parenthesis and simplify left side
15a + 9a + 63 = 327
24a + 63 = 327 ( subtract 63 from both sides )
24a = 264 ( divide both sides by 24 )
a = 11
substitute a = 11 into (2)
c = 11 + 7 = 18
no of people attending = a + c = 11+ 18 = 29