The weights of 4 boxes are 90, 40, 80 and 50 kilograms. Which of the following cannot be the total weight, in kilograms, of any combination of these boxes and in a combination a box can be used only once?
If 'P' means 'divided by', 'T' means 'add', 'M' means 'subtract' and 'D' means 'multiplied by', then what will be the value of the following expression?