There are letter tiles in a bag. Four A's, five B's, six C's and five D's. You select one tile, replace it, and then draw another. P( C and D)=

What are the options

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.