Answer: 60
Explanation:
ball =x
bat = y
x + y = 90
and
equation II is
3 x + 2 y =210
By multiplying by 3 to equation I both sides
we get equation III as
3( x + y) = 3 ( 90 )
3x + 3y =270 III
subtract II and III
we get 3x+3y=270
- 3x+2y=210
--------------------------
0+y= 60
y =60
cost of bat is y ie = 60
and cost of ball ,is
let put value of y in equation I
x+60=90
x=90-60
x=30
cost of ball is 30