Lena has 2 boxes of buttons a and b. in total are 1.200 buttons .she move 360 buttons from box a to b. there are now 3 times as many buttons in box b than box a. homany buttons were in box a at the start?

660

Step-by-step explanation:

Let  A = number of buttons in Box A

and B = number of buttons in Box B

We have two conditions:

(1)            A + B = 1200

(2)       B + 360 = 3(A – 360)     Remove parentheses

          B + 360 = 3A - 1080      Subtract 360 from each side

(3)                 B = 3A - 1440       Substitute (3) into (1)

A + 3A - 1440 = 1200               Combine like terms

      4A - 1440 = 1200               Add 1440 to each side

                4A  = 2640               Divide each side by 4

                   A = 660

15%

step-by-step explanation:

use the table and count the number of guesses that has two correct answers.

the following are two correct answers

10010, 01100, 11000

a total of 3 numbers having 2 correct guesses out of 20 questions.

probability of getting 2 correct guesses = the number of questions getting 2 correct answers / total number of questions.

= 3/20

to convert it into percent multiply by 100, we get

= 3/20 * 100

= 15%

the answer is 15%

you.

127

whether it's diameter, or radius, i believe if i remember correctly from school, every amount has to always add up to 180. so if you take 53, and starting adding, long story short, taking 127 and adding it to 53, gives you 180.