Mathematical Reasoning
A team of three students, Alex, Blake, and Casey, are tasked with labeling 1,500 envelopes. Alex labels 25 en…
Question 1 · Multiple choice
Question
A team of three students, Alex, Blake, and Casey, are tasked with labeling 1,500 envelopes. Alex labels 25 envelopes per hour for 12 hours. Blake then labels 30 envelopes per hour for 15 hours. Casey finishes the rest. What fraction of the total envelopes did Casey label?
Options
- A. 1/2
- B. 11/30
- C. 1/3
- D. 7/15
- E. 1/4
Correct answer
A. 1/2
Explanation
Method 1: Work out how many envelopes each person labelled. Alex labelled 25 envelopes each hour for 12 hours. 25 x 12 = 300 Blake labelled 30 envelopes each hour for 15 hours. 30 x 15 = 450 So Alex and Blake together labelled: 300 + 450 = 750 envelopes There were 1,500 envelopes altogether, so Casey labelled the rest: 1,500 - 750 = 750 envelopes Now write Casey's share as a fraction of the whole job: 750 / 1,500 Divide top and bottom by 750: 750 / 1,500 = 1 / 2 So Casey labelled 1/2 of all the envelopes.