किसी कक्षा में 25 वियार्थीयो के भार का औसत 50kg है । यदि अध्यापक का भार भी समीलीत किया जाए , तो औसत भार 1kg बढ़ जाता है । अध्यापक का भार ज्ञात करे ?

Options

A. 76 kg
B. 77 kg
C. 74 kg
D. 75 kg

Answer

A

Explanation

According to the question
Average weight of 25 students =50 kg
Sum of the weight of 25 students =50x25=1250 kg
If the class teacher included the average is increased by 1 .
`therefore` Average weight of 25 students and teacher =51 kg
`therefore` Sum of weight =26x51=1326 kg
`therefore` Class teacher weight =1326-1250=76 kg
Alternate
If the weight of the class teacher is included the average is increased by 1 kg
`therefore` Total increased in weight =26x1=26 kg
Note: If the weight of class teacher is same as the average weight of 25 students then there would have been no effect on average. But the weight of teacher is more than the average of 25 students weight then average is increased by 1 kg
`therefore` Class teacher's weight =50+26=76 kg