Chapter ISG, Problem 3.6.5P

To determine

To evaluate a day when number of pages A has read is equal to number of pages S is left with

Answer to Problem 3.6.5P

No such day exists.

Explanation of Solution

Given information:

S and A are reading the Se book of 430 pages.

A reads 30 pages every day.

S created the table for his reading,

Day	Pages left
1	430
2	410
3	390
4	370

Function that represents S’s number of pages left,

  $f(x)=430-20x$

Formula used:

Function solving.

Calculation:

For A,

Each day the number of pages increases by 30 pages. Hence, function for number of pages A has read is,

  $f(x)=30x$

For the day, when number of pages A has read is equal to number of pages S is left with

Equating both the function,

  $430-20x=30x$

Shifting left- hand side variables to right hand side,

  $20x+30x=430$

So,

  $50x=430$

Cross multiplying both sides,

  $x=\frac{430}{50}$

On solving,

  $x=8.6$

Hence, value of day is 8.6

Since, the value of day can’t be in decimal. Hence, there is no such day when the number of pages A has read is equal to the number of pages S is left with