The average weight of students in a class of 32 students is 40 kg . If the weight of the teacher be included, the average rises by (1/3) kg , then the weight of the teacher is

Question

The average weight of students in a class of 32 students is 40 kg . If the weight of the teacher be included, the average rises by (1/3) kg , then the weight of the teacher is (A) 40.5 kg (B) 50 kg (C) 41 kg (D) 51 kg

Tardigrade Admin · Accepted Answer

Let, the weight of the teacher be wkg , then 40+(1/3)=(32 × 40 + w/32 + 1) ⇒ 33× 40+33× (1/3)=32× 40+w⇒ w=51 ∴ Weight of the teacher =51 kg

Q. The average weight of students in a class of $32$ students is $40 k g$ . If the weight of the teacher be included, the average rises by $\frac{1}{3} k g$ , then the weight of the teacher is

$40.5 k g$

$50 k g$

$41 k g$

$51 k g$

Let, the weight of the teacher be $w k g$ , then
$40 + \frac{1}{3} = \frac{32 \times 40 + w}{32 + 1}$
$\Rightarrow 33 \times 40 + 33 \times \frac{1}{3} = 32 \times 40 + w \Rightarrow w = 51$
$∴$ Weight of the teacher $= 51 k g$

Q. The average weight of students in a class of 32 students is 40kg . If the weight of the teacher be included, the average rises by 31​kg , then the weight of the teacher is

40.5kg

50kg

41kg

51kg