Question

If the average of six numbers is 10, and five of them are 5, 8, 12, 15 and 17, what is the sixth number? pls help!​

Answer 1

Let X be the sixth number. Then we can set up the following equation to solve for X:

(5 + 8 + 12 + 15 + 17 + X) / 6 = 10

Simplifying the left side, we get:

(57 + X) / 6 = 10

Multiplying both sides by 6, we get:

57 + X = 60

Subtracting 57 from both sides, we get:

X = 3

Therefore, the sixth number is 3