- Question-1
- Explanation

The average number of visitors to a museum from Wednesday to Saturday was 2345. Average number of visitors to it from Thursday to next Sunday was 2100. If the number of visitors to the museum on Sunday was 1820, find the number of visitors to the museum on Wednesday.

** **a) 2700 b)2900 c) 2400 d) 2800

d) 2800

The average number of Visitors from Wednesday to Saturday – 2345

Total Number of Visitors from Wednesday to Saturday – 2345 x 4 = 9380

Average number of visitors from Thursday to Sunday 2100

Total number of visitors from Thursday to Sunday – 2100 x4=8400

Number of visitors on Sunday -1820.

So number of visitors from Thursday to Saturday – 8400 1820=6580

But it is given that, Number of visitors from Wednesday to Saturday – 9380

Therefore, Number of visitors on Wednesday = 9380 6580=2800

- Question-2
- Explanation

A prominent School at Siliguri had three batches of students numbering 35,40 and 50 respectively. The average mark of these batches is 40, 45 and 55 respectively. What is the average mark of all the three batches students put together?

a) 48.6 b) 49.6 c) 51 d) 47.6

**Answer:**

d) 47.6

Total marks of all the three batches = Number of Students in I batch * Average of I batch + Number of Students in II batch * Average of II batch + Number of Students in III batch * Average of III batch = [(35 x40) + (40 x45) + (50 x 55)]

Total number of students in all III batches = 35 + 40 + 50 = 125

Average marks of all students of III batches = Total marks of all 3 batches/Total number of students. = [(35×40) + (40×45) + (50 x 55)] divided by 125 =47.6

- Question-3
- Explanation

Two whole numbers whose sum is 144 cannot be in the ratio:

a)3:4 b)5:7 c) 3:5 d)4:5

**Answer:**

a) 3:4

Let us go option by option. If 144 is to be divided in the ratio of 3:4 then it takes the form

3x + 4x = 144 where x needs to be a whole number Or 7x = 144 and x has to be a whole number. For x to be a whole number, 144 have to be divisible by 7 which is not possible. Hence, 3:4 ratio cannot exist and hence it is the correct answer

- Question-4
- Explanation

A cake seller sells one cake at a profit of 10% and sells another at a loss of 5%. Let the ratio of the CPs of the cakes is 2:3 respectively. Find his net profit or loss percentage.

**Answer:**

Let the CPs of the cakes be 2x and 3x (so that they are in the ration 2:3 as per the question.)

Hence net CP = 5x.

SP of first cake = (110/100)*2x = 220x/100 SP of second cake = (95/1 00)*3x = 285x/1 00

Net SP = (220x/100) + (285x/100) = 505x/100 =5.05x.

SP is greater than CP and his profit is 5.05x – 5x =.05x.

His profit percentage = (.05x/5x) % = .01 %.

- Question-5
- Explanation

Mr. Balamurali spends 25% of his monthly salary on household expenditure, 20% of the remaining on children’s education, and the remaining is equally invested in three different schemes. If the amount invested in each scheme is RS.5600, what is the monthly salary of Balamurali?

a) Rs. 28000 b) RS.21000 c) Rs. 24000 d) Rs. 42000

**Answer: **

a) Rs. 28000.

Let total salary of Mr. Balamurali be Rs. K

Expenditure on household = 25 K/100 Remaining amount = K – Expenditure on household =

K – 25K /100 = 75K / 100 .

20% of the remaining is invested in children’s education. Hence amount invested in Children’s education = (20/100) X (75K/100)

Remaining Amount is invested in three schemes equally (in each scheme RS.5600 is invested.)

Total investment in all three schemes = 3 X 5600 = 16800

Total Salary = K = Expenditure on household + Amount invested in children’s education + Amount invested in 3 schemes

Or K = 25 K/100 + (20/100) X (75K/100) + 16800

Or K = K/4 + 3K/20 + 16800

Solving the above equation, you will get K = Rs. 28000