Chapter 2
Introduction to Linear Polynomials
CBSE Class 9
Mathematics Solutions
Educart Mathematics class Class 9 NCERT Exemplar cover
Question:

What is the cost of travelling 15 km? For how many km will the cost be ₹ 700 (Refer to Example 9 on NCERT page no. 24)?                                                                                                                                                                                           [Page No. 24]

Answer: Verified

The cost function is C(d)=100+60dC(d) = 100 + 60d.

• For 15 km: 100+60×15=100+900=₹ 1000100+60\times15=100+900=\text{₹ }1000.

• For a cost of ₹ 700: 100+60d=700→60d=600→d=10100 + 60d = 700 \rightarrow 60d = 600 \rightarrow d = 10 km.

Notice the cost rises by a fixed ₹ 60 for every extra km that constant increase is what makes it linear growth.

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More NCERT Questions
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