Question

If the average weight of 6 students is 50 kg, that of 2 students is 55 kg and that of rest of 2 students is 55 kg, then the average weight of all the students is ?​

Answer 1

Answer:

$\huge\underline\bold {Answer:}$

Total weight of 6 students = 6 × 50 kg = 300 kg

Total weight of 2 students = 2 × 51 kg = 102 kg

Total weight of 2 students = 2 × 55 kg = 110 kg.

Average weight of all the students = Total weight/Number of students = (300 + 102 + 110) ÷ 10 kg

= 512/10 kg

= 51.2 kg.

Therefore average weight of all students is 51.2 kg.

Answer 2

Step-by-step explanation:

method 1

Average weight of six students=50kg

So total weight of 6 students=50×6=300kgs

Now 2 students are of 55kg and 2 of 51kg=212kgs

Total=212+300=512

Average=512/10=51.2kg

method 2

w1+w2+…+w6)/6=50kg (given)

or,w1+w2+…+w6=50∗6=300kg…(1)

Also,(w7+w8)/2=51kg(given)

or,w7+w8=102kg…(2)

Also,(w9+w10)/2=55kg

or,w9+w10=110kg…(3)

Adding eqns. 1,2 & 3, we get

w1+w2+…+w10=(300+102+110)kg

or, Total weight of all students =512kg

Thus, average weight of all students = (Total weight of all students/Total number of students)

or, Average weight of all students=(512/10)kg

or, Average weight of all students=51.2kg