SAT Math Practice Exam

Answer C Assume the cost of a toy train = m .The cost of a toy car is $20 less than 2 times the cost of a toy train .
The cost of a toy car = 2x m -20.It is given equal to $100
2m -20 = 100 , or 2m = 120 or m =60

Key takeaway: First you convert the word problem into a simple equation with a variable. Then solve simple equation, using mathematical operations such as add, multiply to isolate the variable . Get the variable alone on one side of the equal sign