Question

A young sumo wrestler decided to go on a special high-protein diet to gain weight rapidly. He started at 90 kilograms and gained weight at a constant rate of 8 lbs. a week.

a. Write a function to represent this situation. Use x and y as your variables.
b. What would his weight be after 8 weeks?

Answer 1

a) The function that represent this situation is y = 90 + 8x.

b) His weight be after 8 weeks is 154 lbs.

Explanation:

It is given that,

• He started at 90 kilograms.
• And gained weight at a constant rate of 8 lbs a week.

a) Write a function to represent this situation. Use x and y as your variables.

• Let 'x' be the number of weeks he gained weight.
• Let 'y' be the total weight.

Hence the equation can be framed as,

Total weight = starting weight + weight gained in x weeks.

We know that, each week he gains 8 lbs. Therefore, for 8 weeks he gained 8x lbs of weight.

⇒ y = 90 + 8x.

∴ The function that represent this situation is y = 90 + 8x.

b) What would his weight be after 8 weeks?

To find his week after 8 weeks, substitute x=8 in the function y = 90 + 8x.

⇒ 90 + 8(8)

⇒ 90 + 64

⇒ 154 lbs.

∴ His weight be after 8 weeks is 154 lbs.