Mathematics Question and Answer for Exams
If average of 20 observations x1 , x2 , ....., x20 is y, then the average of x1 – 101, x2 – 101, x3 – 101, ....., x20 –101 is
(A) 20y
(B) 101y
(C) y – 20
(D) y – 101
Correct Answer : D
12 kg of rice costing 30 per kg is mixed with 8 kg of rice costing 40 per kg. The average per kg price of mixed rice is
(A) 35
(B) 34
(C) 38
(D) 37
Correct Answer : B
Explanation :
Gagan started a business and Michael joined him after 2 months. Gagan spent Rs.15000 while Michael spent Rs.27,000. Their one year profit came out to Rs.5000. How much profit will Gagan get?
(A) 3000
(B) 2000
(C) 1500
(D) 2750
Correct Answer : B
A sum of Rs.10600 is divided among P, Q, R in such a way that P gets Rs.1400 more than what Q gets and Q gets Rs.1600 more than what R gets. The ratio of their shares is
(A) 16: 9: 18
(B) 27: 18: 10
(C) 18: 25: 10
(D) 16: 25: 10
Correct Answer : C
The marked price of a Bike was Rs.22500. After allowing two successive discounts, it was sold for Rs.17595. If the second discount was 8%, then what was the first discount?
(A) 12%
(B) 15%
(C) 14%
(D) 9%
Correct Answer : B
A double bed is marked at Rs. 7500. The shopkeeper allows successive discounts of 8%, 5% and 2% on it. What is the Net selling price?
(A) Rs. 18775.26
(B) Rs. 8525.50
(C) Rs. 6452.05
(D) Rs. 6423.90
Correct Answer : D
The product of two numbers is 9375 and the quotient, when the larger one is divided by the smaller, is 15. The sum of the number is:
(A) 395
(B) 380
(C) 400
(D) 425
Correct Answer : C
Explanation :
Let the numbers be x and y and x is greater than y.
As given,
xy = 9375 ....(i)
Again,
∴ From equation (i),
15y × y = 9375
A number divided by 68 gives the quotient 269 and remainder zero. If the same number is divided by 67, the remainder is:
(A) 2
(B) 3
(C) 0
(D) 1
Correct Answer : D
Explanation :
Number = 269 × 68
= 269 × (67 + 1)
= 269 × 67 + 269
Clearly, remainder is obtained on dividing 269 by 67 that is 1.
If pq+qr+rp=0 then find the value of $$ {p^{2}\over {p^{2}-qr}}+{q^{2}\over {q^{2}-rp}}+{r^{2}\over {r^{2}-pq}}$$
(A) 0
(B) 1
(C) -1
(D) 3
Correct Answer : B
If $$ {x+{1\over x}=\sqrt{3}}$$ then $$ {x^{48}+x^{378\over7}+x^{726\over11}+x^{60}}$$ is equal to
(A) 1
(B) 0
(C) -1
(D) 2
Correct Answer : B