Find the missing number in this proportion 63/21=9/?

Frank has a devised a formula for his catering business that calculates the number of meatballs he needs to prepare. the formula is m=4a+2c, where c=number of children; m=number of meatballs; a=number of adults. how many meatballs are required for a party of 10 adults and 5 children?

Acompany made a profit of 75000 over a period of 6 years on an initial investment of 15000 what is the annual roi

The length of an intercepted arc of a central angle of a circle is 4 cm. if the radius of the circle is 5 cm what is the measurement of the central angle to the nearest whole degree