Luis needed to buy some socks. He bought 4 pairs of red socks and 6 pairs of blue ones. In total, he spent $42. If the red socks cost $3 each, how much did he pay for each blue pair?
Let B be the cost of the blue socks
4*3 +6*Y =42
12 + 6*Y=42
6*Y =30
Y = <<5=5>>5
#### 5