27 coins of quarters (25¢) and nickels (5¢) total $3.95. How many nickels are there?

 4 nickels

Step-by-step explanation:

First you need to calculate how many cents there are in 27 quarters.  To do so, you need to multiply 27 by 25 because each quarter is worth 25 cents.  Then divide that answer by 100.  When multiplied the answer should be 675.  675 ÷ 100 = $6.75 which means because nickels equal 5 cents, you would need 4 nickels to make $3.95.

0.16 or 16%

step-by-step explanation:

lets take a coin for example.

if you toss it twice, it has a 1/4 chance of landing on heads both times because 1/2 * 1/2 is 1/4.

with the cards, the chance of picking dog is 0.4. having two people pick one is like picking a card twice in a row. so 0.4 * 0.4 is 0.16, or 16%