Nina has 465 pennies in a jar. Daryl has 348 pennies in a jar. How many pennies do they have in all?

Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

Find the missing dimension! need asap! tiny square is a =3025 in ²