One day at st. philip's high school, 1/2 of the pupils walked to school, 1/5 of the pupils came to school by bus, and the remaining 57 pupils came by car. so then how many pupils are there in the school?

Which expression shows the sum of the polynomials with like terms grouped together

This is about circle theorems. someone asap : (

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.