Answer: 95 children, 68 adults
Step-by-step explanation:
Let the number of children be y
Let the number of adults be z
The following equation can be gotten from the question:
y + z = 163 ...... equation i
1.5y + 2.5z = 312.5 ....... equation ii
Multiply equation I by 1.5
Multiply equation ii by 1
1.5y + 1.5z = 244.5 ......... equation iii
1.5y + 2.5z = 312.5 ........ equation iv
Then subtract equation iv from iii
-z = -68
z = 68
From equation I
y + z = 163
y = 163 - 68
= 95
95 children and 68 adults swam.