it takes cindy 3/4 of an hour to
complete a puzzle. how many
puzzles can cindy finish in 3
hours?

1 hour is equivalent to 60 minutes

3/4 hours is - 60 minutes x 3/4 = 45 minutes

3 hours are equivalent to 60 minutes/hr x 3 hr = 180 minutes

it takes Cindy 45 minutes to complete a puzzle

so it takes her 45 minutes for - 1 puzzle

then in 180 minutes she can make - 1/45 x 180 = 4 puzzles

in 3 hours she can complete 4 puzzles

it is contrapositive

i could not see the question too well so check yourself again too . this is because i want you to get it correct.

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.