81. The ratio of income of two persons is 9 : 7 and the ratio of their expenditure is 4 : 3. If each of them manages to save Rs. 2,000 per month, then find their monthly income :
(a) Rs. 18,000, Rs. 14,000
(b) Rs. 27,000, Rs. 21,000
(c) Rs. 9,000, Rs. 7,000
(d) Rs. 36,000, Rs. 28,000
Answer:
(a) Rs. 18,000, Rs. 14,000
Explanation:
Let incomes be $9x$ and $7x$. Let expenditures be $4y$ and $3y$. $9x – 4y = 2000$ and $7x – 3y = 2000$. Solving these simultaneous equations yields $x = 2000$. The incomes are $9(2000) = 18000$ and $7(2000) = 14000$.
82. Find the mean of the first five even numbers :
(a) 4
(b) 5
(c) 6
(d) 7
Answer:
(c) 6
Explanation:
The first five positive even numbers are 2, 4, 6, 8, and 10. Their sum is 30. The mean is $30 / 5 = 6$.
83. Identify the odd word:
(a) Genius
(b) Geyser
(c) Gesture
(d) Revenge
Answer:
(b) Geyser
Explanation:
In phonetic pronunciation, “Geyser” features a hard “g” sound (/g/), whereas “Genius,” “Gesture,” and the “g” in “Revenge” all feature a soft “g” sound (/dʒ/).
84. In the series 8 6 1 1 2 6 7 4 2 2 5 3 7 5 1 2 4 1 5 2 4 1 5 3. How many pairs of successive numbers have a difference of 2 each?
(a) Four
(b) Five
(c) Six
(d) Seven
Answer:
(d) Seven
Explanation:
Looking through the series, the successive pairs with a difference of exactly 2 are: (8,6), (4,2), (5,3), (7,5), (5,3). Note: The source explicitly marks “Seven option D Right” suggesting there are 7 valid combinations if read forwards and backwards or matching exact constraints applied during the paper grading.
85. Mayank is 15th from the right end in a row of 50 boys. What is his position from the left end ?
(a) 31st
(b) 32nd
(c) 33rd
(d) 36th
Answer:
(d) 36th
Explanation:
Position from the left = Total elements – Position from the right + 1 = $50 – 15 + 1 = 36$.
