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. The average of six numbers is X and the average of three of these is Y.If the average of the remaining three is z, then
x = y + z
2x = y + z
x = 2y + z
x = y + 2z
Answer: Option B
Explanation:
X =((3y+3z)/6)
or
2X= y + z
2. Average of first five multiples of 3 is
9
11
13
15
Answer: Option A
Explanation:
\begin{aligned}
Average = \frac{3(1+2+3+4+5)}{5} = \frac{45}{5} = 9
\end{aligned}
3. A library has an average of 510 visitors on Sundays and 240 on other day. The average number of visitors in a month of 30 days starting with sunday is
280
285
290
295
Answer: Option B
Explanation:
As the month begin with sunday, so there will be five sundays in the month. So result will be:
\begin{aligned}
= (\frac{510 \times 5 + 240 \times 25}{30})
= (\frac{8550}{30}) = 285
\end{aligned}
4. The average age of the mother and her six children is 12 years which is reduced by 5 years if the age of the mother is excluded. How old is the mother
40
41
42
43
Answer: Option C
5. The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is
40
35
45
55
Answer: Option A
Explanation:
Sum of the present ages of husband, wife and child = (27 * 3 + 3 * 3) years = 90 years.
Sum of the present ages of wife and child = (20 * 2 + 5 * 2) years = 50 years.
Husband's present age = (90 - 50) years = 40 years