Jessy pastes stamps for 160 envelopes in 2 hours. If she pastes the stamps at the same rate, for how many envelopes can she paste stamps in 30 minutes ?

2 hours=160

1 hours=160÷2=80

30 minutes=80÷2=40

She can paste 40 stamps in 30 minutes

1.4

2.3

step-by-step explanation:

the formula for the constant of variation is

y= kx

divide each side by x

y/x =kx/x

y/x =k

we know a and y

1.   y/x = k

4/1 =4

check the other values to make sure they are the same

8/2 = 4   12/3 =4   and 16/4 =4  

the constant of variation is 4

2.   y/x = k

3/1 =3

check the other values to make sure they are the same

6/2 = 3   9/3 =3   and 12/4 =3  

the constant of variation is 3

step-by-step explanation: