Frances enjoys consuming both milk and juice. Each glass of milk costs PM=$1 , and each glass of juice costs PJ=$2 . Suppose that Frances buys 30 glasses of milk and 20 glasses of juice per week. The following graphs show her marginal utility curves for milk and juice. At her current consumption level, Frances's marginal utility from consuming the last glass of milk she bought is MUM=12 utils per glass, and her marginal utility from consuming the last glass of juice she bought is MUJ=12 utils per glass