Question

Jaime is preparing for a bicycle race. His goal is to bicycle an average of at least 280 miles per week for 4 weeks. He bicycled 240 miles the first week, 310 miles the second week, and 320 miles the third week. Which inequality can be used to represent the number of miles, x, Jaime could bicycle on the 4th week to meet his goal?

• A. $\frac{240+310+320}{3}+x\ge 280$
• B. $240+310+320\ge x\left(280\right)$
• C. $\frac{240}{4}+\frac{310}{4}+\frac{320}{4}+x\ge 280$
• D. $240+310+320+x\ge 4\left(280\right)$

Answer 1

The correct option is D $240+310+320+x\ge 4\left(280\right)$

If Jamie cycles x miles on the last week, the average number of miles per week is $\frac{240+310+320+x}{4}$. Since the average number of miles should be at least be 280,
$\frac{240+310+320+x)}{4}\ge 280$
$\Rightarrow 240+310+320+x=4\left(280\right)$