If z varies directly as x and inversely as y and is equal to 4 when x and y have the values 12 and 8 respectively, what is the value of z when x is equal to 6/7 and y is equal to 5/28?

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

Use multiples to write two fractions equivalent to 7/9. 14/18, 8/10 6/8, 21/27 10/12, 28/36 14/18, 21/27

Titus works at a hotel. part of his job is to keep the complimentary pitcher of water at least half full and always with ice. when he starts his shift, the water level shows 4 gallons, or 128 cups of water. as the shift progresses, he records the level of the water every 10 minutes. after 2 hours, he uses a regression calculator to compute an equation for the decrease in water. his equation is w –0.414t + 129.549, where t is the number of minutes and w is the level of water. according to the equation, after about how many minutes would the water level be less than or equal to 64 cups?