Find the range of the possible values of the variable? ! [see picture]

Calculate the effective quarterly compound interest rate equivalent to a 1% of monthly compound interest rate.

Shannon mary and john earn a weekly allowance ahannon earns the amount that is 2/3 of what john earns mary earns an amount that is 1 2/3 of what johns earns 20 dollars a week who eaens the greatest allowance and who earns the least

X+y ≥20 x≤2y a) (0,22) b) (7,11) c) ( 15,6) d) (10,10) e) (12,5) f) (8,16)