In the school the ratio of the number of pupils to the number of teacher is 20:1 if the number of pupils is 840 how many teacher are there

Problem melissa is her dad build a walkway in their backyard. the walkway will be 54 feet long and 1.5 feet wide. the local hardware store sells tiles which are 1.5 by 1.5 feet and come in boxes of 12. how many boxes of tiles do they need?

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?

Write 17/20 as a decimal and as a percent.