The weights of 4 boxes are 20, 30, 50 and 70 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?
A man is engaged for planting trees for 10 hours. He plants 10 trees in an hour. He takes rest for 30 minutes after every hour. How many trees does he plant in 10 hours?
Pointing to a lady in a photograph, Meera said, "Her father's only son's wife is my mother-in-law". How is Meera's husband related to that lady in the photo?