Rohan has a box of 60 chocolates. He eats 4 chocolates every day. Find the number of chocolates Class 9

Rohan has a box of 60 chocolates. He eats 4 chocolates every day. Find the number of chocolates Class 9

Question 1.

Rohan has a box of 60 chocolates. He eats 4 chocolates every day. Find the number of chocolates remaining after 7 days. After how many days will he be left with only 20 chocolates? Class 9

Solution:

Let n denote the number of days

As the value of n increases by one day, the number of chocolates decreases by a fixed amount of 4.

Therefore, this is an example of linear decay. The linear expression for number of chocolates remaining is C(n) = 60 - 4n

Substituting n = 7 in C (n), we get

C(7) = 60 - 4 × 7 = 60 - 28 = 32 chocolates

Given,

Number of remaining chocolates C(n) = 20

∴ 60 - 4n = 20

∴ 4n = 60 - 20 = 40

∴ n = [latex]\frac{40}{40}[/latex] = 10 days

∴ Rohan will be left with 20 chocolates after 10 days.

[Note: Here C(n) means C is a linear function of n i. e:, C is a linear expression in terms of n and not C × n]