At a fair cake-eating contest, Bobby ate three cakes in 20 minutes. At the same speed, how long did it take to win the contest by eating twenty-one cakes? Give your answer in minutes

140 minutes

Step-by-step explanation:

First divide 21 by 3 to get 7

Then do 20*7 to get 140 :)

2 hours and 20 minutes.

Step-by-step explanation:

20 minutes is ⅓ of a full hour. This means that 20 x 3 is equal to the number of minutes in a hour. So, Let's find out how much thirds 21 is equal to. We will divide 21 by 7.

21 divided by 7 is equal to 3.

The answer to the question is 2 hours and 20 minutes.

option 1 is correct.

step-by-step explanation:

y varies inversely with x and constant of variation is 4

the equation will be:

y = k/x

where k =4 so,

y = 4/x

if we put values of x of option 1 in the above equation and find values of y

y = 4/-2 => y =-2

y = 4/-1 => y = -4

y = 4/1 => y = 4

y = 4/2 => y =2

so, all the values of x and y are correct.

if we put values of x given in other options and find value of y we cannot find whole table satisfying the equation.

hence option 1 is correct.

a

step-by-step explanation: