Problem number 7 states, in a jazz band, Giuseppe plays the saxophone, Sergio plays the trumpet, and Elena sings. They are all the same age. There are three more members of the jazz band who are 19, 20, and 21 years old. The average age of the jazz band is 21. How old is Elena? So we have Giuseppe, Sergio, and Elena, who have all the same age in this jazz band. We'll let their age be represented by the variable A. Then we have three other folk, who are 19, 20, and 21. The question asks about the average of their age, so let's do that by adding up all their ages and dividing by the number of people in the sample, so 6. The problem tells us that this number should be equal to 21. Now I have an equation, so let's solve for A. First let's combine the like terms in the numerator. Next let's get rid of the fraction by multiplying both sides by 6, subtract 19, 20, and 21 for both sides, and finally divide by 3 to get A equals 22. This means that Giuseppe, Sergio, and Elena were all 22 years old. The question asks specifically about Elena's age, so her age is 22. So the question asks us, how old is Elena? The answer is 22 years old. Letter C.

jazz band

average age

Elena

solve equation

age calculation