Marcus finished 2/3 of his test in 1/2 hour. Express this rate in hours per test

Question

Marcus finished 2/3 of his test in 1/2 hour.  Express this rate in hours per test.

Answer 1

2/3 test         1 test

----------- = ------------

 1/2 hour           ?

 

 

Cross multiplies:

 

 2/3 * ? = 1/2 * 1

 

2/3 * ? = 1/2

 

? = 3/2*1/2 = 3/4

 

1 test takes 3/4 hours or 45 minutes

 

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Another way to look at it is :

 

2/3 of the test in 1/2 hour (or 30 minutes)

 

1/3 of the test in 1/4 hour (or 15 minutes) <--- divides everything by 2.

 

1 test in 3/4 hours <--- multiplies everything by 3.