A person spends Rs. 8100 in buying some tables at Rs. 1200 each and some chairs at Rs. 300 each. The ratio of the number of chairs to that of tables when the maximum possible number of tables is purchased,
(A) 1 : 2
(B) 1 : 4
(C) 2 : 1
(D) 5 : 7
Solution:
Maximum possible number of tables = 6 [∵ 1200 × 6 = 7200] Number of chairs purchased
72.
One year ago the ratio of the ages of Sarika and Gouri was 3 : 4 respectively. One year hence the ratio of their ages will be 10 : 13 respectively. What is Sarika's present age ?
(A) 18 years
(B) 20 years
(C) 26 years
(D) Cannot be determined
Solution:
Answer & Solution Answer: Option E Solution: Let Sarika's and Gauri's ages one year ago be 3x and 4x years respectively Sarika's age 1 year hence = (3x + 2) years Gauri's age 1 year hence = (4x + 2) Hence, Sarika's present age = 3x + 1 = (3 × 6 + 1) years = 19 years
73.
Two bottles contain acid and water in the ratio 2 : 3 and 1 : 2 respectively. These are mixed in the ratio 1 : 3. What is the ratio of acid and water in the new mixture = ?
(A) 7 : 13
(B) 11 : 57
(C) 23 : 37
(D) 1 : 3
Solution:
Let 1 bottle of acid is 30litre and consider the first bottle as A and second bottle as B. Ratio of Acid and water in bottle A = 2 : 3 Volume of Acid in bottle A = Volume of Water in bottle A = Ratio of Acid and water in bottle A = 1 : 2 Volume of Acid in bottle A = Volume of Water in bottle A = Now 1 bottle of A and 3 bottles of B mixed together Volume of Acid in new mixture = 12 + 3 × 10 = 42 Volume of water in new mixture = 18 + 3 × 20 = 78 Ratio of Acid and water in new mixture = 42 : 78 = 7 : 13
74.
In two alloys A and B the ratio of Zinc and Tin is 5 : 2 and 3 : 4 respectively. 7 kg of the alloy A and 21 kg of the alloy B are mixed together to form a new alloy. What will be the ratio of Zinc and Tin tin the new alloy ?
(A) 2 : 1
(B) 1 : 2
(C) 2 : 3
(D) 1 : 1
Solution:
Zinc : Tin A 5x : 2x = 7x B 3y : 4y = 7y ⇒ A ⇒ 7x = 7 kg x = 1 kg ∴ Zinc in alloy A ⇒ 5kg Tin in alloy A ⇒ 2 kg ⇒ B ⇒ 7y = 21 kg y = 3 kg Zinc in alloy B ⇒ 3 × 3 = 9 kg Tin in alloy B ⇒ 3 × 4 = 12 kg ∴ After mix - up the ratio of Zinc and Tin in new alloy
75.
The ratio of the income of A and B in the last year was 4 : 3. The
ratios of their individual incomes in the last year and the present year are 3 : 4 and 5 : 6, respectively. If their total income in the present year in Rs. 24.12 lakhs, then the sum of the income (in Rs. lakh) of A in the last year and that of B in the present year is:
(A) 22.17
(B) 10.98
(C) 20.52
(D) 21.28
Solution: The ratio of income of A and B in the last year is 4 : 3. So we're making last year's income 60, 45. Present age ratio of both = 80 : 54 Sum of present age of both = 80 + 54 = 134 units 134 units → 24.12 lakh 1 unit → Sum of income of A in final year and income of B in present year = 60 + 54 = 114 114 units → × 114 = 20.52 Sum of income of A in final year and income of B in present year = 20.52 lakh Alternate solution A's present salary : Ratio of final year to present year = 3 : 4 3 units = 4x 4 units B's present salary : Final year and present year = 5 : 6 5 units = 3x 6 units Final year income of A and Present year income of B. Final year income of A and Present year income of B = 20.52 lakh
76.
If ÃÂÃÂ ÃÂÃÂ then
(A) 12 : 9 : 8
(B) 9 : 8 : 24
(C) 8 : 9 : 24
(D) 9 : 12 : 8
Solution:
77.
Which of the following represents ab = 64?
(A) 8 : a = 8 : b
(B) a : 16 = 6 : 4
(C) a : 8 = b : 8
(D) 32 : a = b : 2
Solution:
A = 8 : a = 8 : b ⇒ 8a = 8b ⇒ a = b. B = a : 16 = b : 4 ⇒ 4a = 16b ⇒ a = 4b C = a : 8 = b : 8 ⇒ 8a = 8b ⇒ b = a D = 32 : a = b : 2 ⇒ ab =64
78.
If A : B = 7 : 9 and B : C = 3 : 5 then A : B : C is equal to = ?
(A) 7 : 9 : 5
(B) 21 : 35 : 45
(C) 7 : 9 : 15
(D) 7 : 3 : 15
Solution:
Given, A : B = 7 : 9 B : C = 3 : 5 Equal the value of B in both equation B : C = 3 : 5 (multiply with 3) i.e. B : C = 9 : 15 ∴ A : B : C = 7 : 9 : 15
79.
The ratio of ducks and frogs in a pond is 37 : 39 respectively. The average number of ducks and frogs in the pond is 152. What is the number of frogs in the pond ?
(A) 148
(B) 152
(C) 156
(D) 144
Solution:
Ratio of Ducks and Frogs in Pond = 37 : 39 Average of Ducks and Frogs in Pond = 152 So, total number of Ducks and Frogs in the Pond = 2 × 152 = 304 ∴ Number of Frogs = = 156
80.
The ratio of milk to water in three containers of equal capacity is 3 : 2, 7 : 3 and 11 : 4 respectively. The contents of the three containers are mixed together. What is the ratio of milk to water after mixing ?