Answer: 9 Four Wheel and 3 6 Wheel Trucks
Explanation:
Let FW be the four-wheel trucks and SW the six-wheel trucks.
Total wheels is 4*FW + 6*SW and is equal to 54 wheels
We know that FW = 3*SW, so substitute that into the above equation:
4*3*SW + 6*SW = 54
12*SW +6*SW = 54
18*SW = 54
SW = 3
Therefore FW = 3*3 = 9
FW 4 x 9 = 36 wheels
SW 6 x 3 = 18 wheels
Total = 54 wheels