The average weight of a class of 24 students is 35 kg. If the weight of the teacher be included, the average rises by 400 g. The weight of the teacher is
45
50
55
60
Answer: Option A
Similar Questions :
1. A batsman makes a score of 87 runs in the 17th match and thus increases his average by 3. Find his average after 17th match
36
37
38
39
Answer: Option D
Explanation:
Let the average after 17th match is x
then the average before 17th match is x-3
so 16(x-3) + 87 = 17x
=> x = 87 - 48 = 39
2. Average weight of 10 people increased by 1.5 kg when one person of 45 kg is replaced by a new man. Then weight of the new man is
50
55
60
65
Answer: Option C
Explanation:
Total weight increased is 1.5 * 10 = 15.
So weight of new person is 45+15 = 60
3. The average weight of a class of 24 students is 35 kg. If the weight of the teacher be included, the average rises by 400 g. The weight of the teacher is
45
50
55
60
Answer: Option A
4. A motorist travel to a place 150 km away at an avearge speed of 50 km/hr and returns ar 30 km/hr.His average speed for the whole jouney in km/hr is
36.5 km/hr
37.5 km/hr
35.5 km/hr
34.5 km/hr
Answer: Option B
Explanation:
Average speed will be
\begin{aligned}
\frac{2xy}{x+y} km/hr
= \frac{2(50)(30)}{50+30} km/hr \end{aligned}
= 37.5 km/hr
5. Average of 10 numbers is zero. At most how many numbers may be greater than zero