the total heigh of bill mary and rob is 180 cm bob is twice as tall as bill and mary is 28 cm taller than bill how tall is rob

Answer:Rob is 76 cm tall.Step-by-step explanation:Let b = height of bill.Let m = height of Mary.Let r = height of Rob."the total heigh of bill mary and rob is 180 cm"b + m + r = 180         Equation 1"bob* is twice as tall as bill"*I think you meant Rob is twice as tall as Bill.r = 2b"mary is 28 cm taller than bill"m = b + 28Substitue r = 2b and m = b + 28 into Equation 1.b + b + 28 + 2b = 1804b + 28 = 1804b = 152b = 38r = 2br = 2(38) = 76Rob is 76 cm tall.