Introduction to Direct Proportion

If you need to serve 2 hours of detention for every day you are late for school, the number of hours of detention you serve are directly proportional to the number of days you are late for school.

• True!

• False

If a baby's height increases by 2 cm in the first month after it was born and another 2 cm in the second month after it was born, its height is directly proportional to the number of months that it has been born.

• True!

• False

If you work at a bubble tea shop and are paid a basic salary of $100 a day plus $0.03 for every cup of bubble tea you sell , your earnings are directly proportional to the number of cups of bubble tea sold.

• True!

• False

If the amount of energy in your phone's battery decreases by 5% of its total charge every 2 hours, the amount of energy used is directly proportional to the time that passes.

• True!

• False

It is given that j is directly proportional to m. Given that j = 0.18 when m = 0.06, express j in terms of m.

The price of some apples is directly proportional to the number of apples bought. 5 apples cost $4.25. How much would 47 such apples cost?

Ans: $ _____________

It is given that p is directly proportional to q. When q = 12, p = 2.4. Find the value of p when q = 33