I need help simple interest life project

What two criteria are needed for triangles to be similar

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days

The ivring berlin learning center would like a possible net profit of $650,000 on its new resource manual it sells to schools. the fixed costs for producing the manual are $780,000 and the variable cost per package is $19.85. if the estimated unit sales are 1,250,000 units, what selling price unit should the ivring berlin learning center try?