How to define when something is certain to happen?

If a student thinks of a number from 1 to 75, what is the probability that the number will be 20, 30, or 40?

Definition of standard form

3 purple blocks, 3 yellow blocks, 6 green blocks, and 4 red blocks. Her favorite game is to stack all of the blocks one on top of the other. How Many ways can she do this?

Para una reunion taliana encargo 6 docenas de sandwiches la mitad son de tomate, un tercio de pollo y el resto d jamon y queso. Cuantos sandwiches de pollos habia

800m or 799,999mm which is greater

Susan bought 1 kilogram bag of grapes

Rob bought one jar of sun-dried tomatoes for $4. How many jars can Mofor buy if he has $8?

What is 20.35 divided by 3 in the standard algorithm

A stadium must have 10 attendants at the stadium parking lot and two each at the satellite lots. each attendant makes $10/hour.

Dixon and his little sister Ariadne stand next to each other on the playground on a sunny afternoon. Their mother measured their shadows. Dixon's shadow is 18 feet long and is 18 feet long and ariadne's shadow is 15 feet long.