Xvaries directly as y, and x = 153 when y = 9. find x when y = 13.

a: 106

b: 157

c: 221

The value of x is 221 when  k = 17 and  y = 13.

Therefore the Option (C) is correct .

Step-by-step explanation:

As given

x varies directly as y.

x = ky

Where k is the constant of proportionality.

As given

x = 153 when y = 9

Put in the above

153 = 9k

k = 17

Now Find out the value of x when k = 17 and  y = 13.

x = ky

x = 17 × 13

x = 221

The value of x is 221 when  k = 17 and  y = 13.

Therefore the Option (C) is correct .

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500