<PRE><B>Question 1149364</B>
let x be the number of adults and y be the number of children
:
(1)  x + y = 280
:
(2) P60x + P25y = P14,000
:
solve equation 1 for x and subsitute in equation 2
:
x = 280 - y
:
P60(280 - y) +P25y = P14,000
:
P16,800 - P60y + p25y = P14,000
:
P2,800 -P35y = 0
:
p35y = P2,800
:
y = P2,800/P35 = 80
:
**********************************
80 children attended that day
**********************************
:</PRE>