Lili has 20 friends. Among them are Kevin and Gerry, whoare husband and wive. Lili wants to invite 6 of her friends to her birthdayparty. If neither Kevin nor Gerry will go to a party without the other, howmany choices does Lili have?

Aball is dropped from a height of 10m above the ground. it bounce to 90% of its previous height on each bounce. what is the approximate height that the ball bounce to the fourth bounce?

You just purchased two coins at a price of $670 each. because one of the coins is more collectible, you believe that its value will increase at a rate of 7.1 percent per year, while you believe the second coin will only increase at 6.5 percent per year. if you are correct, how much more will the first coin be worth in 15 years?

Si el duplo del mayor de dos numeros se divide entre el el triplo del menor, el cocient es 1 y el residuo 3, y si 8 veces el menor se divide por el mayor, el cociente es 5 y el residuo 1