# The cost of a notebook is Rs 10. Draw a graph after making a table showing cost of 2, 3, 4, .... note books. Use it to find

(a) the cost of 7 notebooks.

(b) The number of note books that can be purchased with Rs 50.

**Solution:**

The table below shows the cost of various quantities of note books.

No. of Notebooks | 1 | 2 | 3 | 4 | 5 |

Cost (@ Rs. 10) | 10 | 20 | 30 | 40 | 50 |

The graph of the table is given below:

(a) From the graph we can see that the cost of 7 books can be found out by drawing a vertical line from horizontal axis(no.of notebooks) to the straight line AB(at C). From point C we draw a horizontal line to the vertical axis. The cost of 7 note books is Rs.70.

(b) How many books can be purchased can be found out by drawing a horizontal line from the vertical axis to the line AB(at point D). From the point D we drop the vertical line to the horizontal axis. We can note that the number of book that can be bought for Rs.50 and is 5.

(a) From the graph we can see that the cost of 7 books can be found out by drawing a vertical line from horizontal axis(no.of notebooks) to the straight line AB(at C). From point C we draw a horizontal line to the vertical axis. The cost of 7 note books is Rs.70.The graph of the table is given below:

**✦ Try This: **The distance covered by a truck for a given average speed is given by the table below:

Distance Covered (km) | 40 | 80 | 120 | 160 |

Time (hours) | 1 | 2 | 3 | 4 |

(a) what will be distance covered in 3.5 hours From the graph find

(b) Time taken to cover 90 km

(a) From the graph below if we draw a vertical line from the horizontal axis which touches the line AB at C. From C a horizontal line is drawn to the vertical axis to get the distance covered in 3.5 hours i.e. 140km

(b) The time taken to travel 90 km can be found out from the graph by drawing a horizontal line from the vertical axis to point D on the line AB. From point D if a vertical line is dropped on the horizontal axis the answer obtained is 1.5 hours.

**☛ Also Check: **NCERT Solutions for Class 8 Maths Chapter 15

**NCERT Exemplar Class 8 Maths Chapter 12 Problem 46**

## The cost of a note book is Rs 10. Draw a graph after making a table showing cost of 2, 3, 4, .... note books. Use it to find, (a) the cost of 7 notebooks, (b) The number of note books that can be purchased with Rs 50.

**Summary:**

The graph of the given table is straight line which gives the cost of 7 books as Rs. 70 and the number of notebooks that can be purchased for Rs. 50 is 5.

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