Question

To avoid another plane, the captain ascended 20/49 mile in 6/7 minutes. What was the plane’s average change of altitude in miles per minute?

Answer 1

10/21

Explanation:

So the rule for change of altitude is

Distance / time.

Now insert the numbers into the rule.

Distance/time = (20/49)/(6/7)

Now divide the fractions.

To divide fractions, you must make the denominators match. You do this by finding the LCM. The LCM of the two numbers is 49.

Now times the numerator by what you multipled the denominator so:

Since 7 x 7 then 6 x 7

So 6 x 7 = 42 and 7 x 7 is 49

6/7 = 42/49

20/49 stays the same as it already has the right denominator.

Now to divide fractions you use the rule:

Keep Change Flip

(20/49)/(6/7)

So 20/49 stays the same.

Now you change the division mark to a multiplication mark.

So now instead of dividing we multiply

Now lastly, we flip the last fraction.

So instead of 6/7 we have 7/6

So our equation is now:

20/49 x 7/6

Now multiply the fractions.

The answer is 10/21

Average change of altitude is 10/21