Question

While riding her bike to the ocean and back home 6 times, Christine timed herself at 65min, 53min, 56min, 50min, 63min, and 56min. She had set a goal of averaging 57 minutes for her rides. How many minutes will she need to spend on her seventh ride to attain her goal?

Answer 1

Let the time taken for seventh ride be x.

Now,

Average time

$= \frac{65 + 53 + 56 + 50 + 63 + 56 + x}{7}$

Or,

$57 = \frac{65 + 53 + 56 + 50 + 63 + 56 + x}{7}$

Or,

$399 = 343 + x$

•°•

$\: x = 56$

So, she need to spend 56 minutes on her seventh ride.