Average temperature of first 4 days of a week is 6°C and that of the last 4 days is 40.3°C. If the average temperature of the week be 39.1°C, the temperature on 4th day is? Pick:
A) 36.7°C
B) 38.6°C
C) 39.8°C
D) 41.9°C
E) 51.9°C
Let temperature on 4th day be X°C   Therefore, 4 x 38.6 + 4 x 40.3 - X = 7 x 39.1   =&gt; X = 41.9   Therefore, temperature on 4th day = 41.9°C.   ANSWER:41.9°C
<result>D</result>
Average temperature of first 4 days of a week is 6°C and that of the last 4 days is 40.3°C. If the average temperature of the week be 39.1°C, the temperature on 4th day is?