the average earning of a person for the first 4 days of a week is rs 18 and for the last 4 days is rs 22. if he earns rs 20 on the fourth day, his average earning for the whole week is?  Select:
A) rs 18.95 B) rs 16 C) rs 20 D) rs 25.71 E) none of these
<gadget id="calculator">4 * 18</gadget>
<output>72</output>

<gadget id="calculator">4 * 22</gadget>
<output>88</output>

<gadget id="calculator">72 + 88</gadget>
<output>160</output>

<gadget id="calculator">160 - 20</gadget>
<output>140</output>

<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">140 / 7</gadget>
<output>20</output>

<result>C</result>
the average earning of a person for the first 4 days of a week is rs 18 and for the last 4 days is rs 22. if he earns rs 20 on the fourth day, his average earning for the whole week is?
divide(subtract(add(multiply(4, 18), multiply(4, 22)), 20), add(const_4, const_3))
total earning for the week = rs ( 4 × 18 + 4 × 22 - 20 ) = rs 140 average earning = rs 140 / 7 = rs 20 . answer : c