Answer:
16 had the cheaper ticket
Step-by-step explanation:
Let the number of 75cents tickets be x
Let the number of $1.25 tickets be y
Since the total tickets is 40, hence;
x+y =40 .... 1
Also if some are sold at 75 cents and the rest at $1.25 with total of $42 earned, then;
0.75x+1.25y = 42... 2
From 1
x = 40-y
Substitute into 2;
0.75(40-y)+1.25y = 42
30-0.75y+1.25y = 42
30+0.5y = 42
0.5y =42-30
0.5y = 12
y = 12/0.5
y = 24
Since x = 40-y
x = 40-24
x = 16
The number of cheaper ticket are 16