Answer:
a. see below
b. Rita: 300; John: 900; Rodell: 925
c. Rita: L; John: 3L; Rodell: 3L+25
d. L +3L +(3L+25) = 2125
e. Rita: $600; John: $1800; Rodell: $1850
Explanation:
Since John's number of laps is expressed in terms of Rita's number of laps, it makes a certain amount of sense to use Rita's laps as a unit of measure. We don't yet know what that unit of measure is, but we can use it to describe both John's laps and Rodell's laps. Rodell will have 25 additional laps added to the 3 units that match John's laps.
Altogether, these 7 units +25 laps will match the total of 2100 +25 laps. It is pretty clear that 1 unit will be 2100/7 = 300 laps. This is shown in the attachment.
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a) The attachment matches the above description.
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b) 1 unit of 300 laps is the number of laps Rita swam. Then John's 3 units correspond to 3×300 = 900 laps, and Rodell's laps will be 25 more than John's, so 925.
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c) In this part, we define 1 unit as L, so the three contributors are ...
- Rita: L
- John: 3L
- Rodell: 3L+25
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d) The equation shows that the sum of the parts is equal to the whole:
L + 3L + (3L+25) = 2125
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e) The numbers of part (b) get multiplied by $2, so are ...
- Rita: $600
- John: $1800
- Rodell: $1850