Tom takes exactly 30 minutes to rake a lawn and his son Mike takes exactly 60 minutes to rake the same lawn. If Tom and Mike decide to rake the lawn together, and both work at the same rate that they did previously, how many minutes will it take them rake the lawA. 16 b. 20

c. 36

d. 45

e. 90

b) 20 minutes

Step-by-step explanation:

Tom=0.5Mike

in 15 minutes, Tom will have done 1/2 of the lawn

in 15 minutes, Mike will have done 1/4 of the lawn

in 15 minutes, they will have done 3/4 of the lawn

15/3=5 minutes for 1/4 of the lawn to be done

5x4=20 minutes for the entire lawn

let x be the money she spent so that she can earn the free t-shirt.

since, she already spent $112.49

⇒

also, as per the statement: jennifer must spend $250 or more in order to qualify for a free t-shirt at the store.

then,

we have an inequality i.,e

subtract 112.49 from both sides we get;

therefore, $137. 51 more money does jennifer need to spend so that she can earn the free t-shirt