Question

Last night, Roberto spent 90 minutes doing homework, 2/3 hour reading, and 540 seconds making his lunch for the next day. How many more minutes did Roberto spend doing homework than he did reading and making his lunch?

Answer 1

41

Explanation:

Ok, so the time for homework is already simplified to minutes.

2/3 of an hour is x/60

60/3 = 20

20*2 = 40

so 2/3 = 40/60

40/60 = 40 minutes

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540 seconds is..

540/60

54/6=9

9 minutes

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40+9 = 49

90-49 = 41

So, he spent 41 more minutes on homework than on making lunch and reading.