Mrs. douglas wanted to give each of her students 3 fancy pencils. she has 20 students. if fancy pencils come in packs of 12, how many packs does she need to purchase so that all of her students get their pencils?

Kyle and elijah are planning a road trip to california. their car travels 3/4 of a mile per min if they did not stop driving, how many miles could kyle and elijah drive in a whole day? ? 1 day = 24 hours. plzzz i will give you 100 points

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.

Math i have no idea how to do a and b