Explain how using basic facts can you find 10x20x30x40 mentally

This week, conrad will work 1 3/4 times longer than last week. giovanni will work 1 1/3 times longer than last week. sally will work 2/3 the number of hours she worked last week. match each employee's name to the number of hours he or she will work this week

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

Anew shopping mall is gaining in popularity. every day since it opened, the number of shoppers is 5% more than the number of shoppers the day before. the total number of shoppers over the first 10 days is 1258 how many shoppers were on the first day?