1. The ratio of Ekta’s and Reema’s income last year was 10: 3. The ratio of Ekta’s this year income and last year income is 6: 5 and the ratio of Reema’s this year income and last year income is 2: 3. If the sum of Ekta’s and Reema’s present incomes is Rs. 5124, what was Reema’s income last year?
A. 1830
B. 1370
C. 1372
D. 1098
Answer - Option D
Explanation -
Let Ekta’s and Reema’s current income be 6x and 2y respectively
Hence, their last year income was 5x and 3y respectively.
Since the ratio of their income last year was 10 : 3
5x : 3y = 10: 3
x = 2y
The sum of Ekta’s and Reema’s present incomes is Rs. 5, 124
6x + 2y = 5124
7x = 5124; x = 732 and y = 366
Therefore, Reema’s income last year = 3y = Rs. 1098
So option (D) is the correct answer.
2. A, B and C invested in the ratio 5:6:8 respectively. If C invested for “x” month and A and B invested for one year. At the end of the year C’s profit is Rs. 3200 and difference between the profit of A and B is Rs. 600 then what is the value of “x”?
A. 4 months
B. 3 months
C. 6 months
D. 8 months
Answer - Option D
Explanation -
Let A, B & C invested in the ratio of 5a,6a & 8a respectively and the total profit be P.
Their investment period is 12, 12 & x months respectively.
Hence, the total investment is [latex](5a \times 12) + (6a \times 12) + (8a \times x)[/latex]
The difference in the profits of A & B is Rs 600.
[latex]\frac {(6a \times 12) - (5a \times12)}{(6a \times 12) + (5a \times 12) + (8a \times 12)}[/latex]
[latex]\frac {12a}{132a + 8ax}P[/latex]= 600
Profit earned by C is Rs. 3200
[latex]\frac {(8a \times x)}{(6a \times 12) + (5a \times 12) + (8a \times 12)}P[/latex] = 3200
[latex]\frac {(8ax)}{(132a \times 8ax)}[/latex] = 3200
By dividing the two equations obtained, we will get:
[latex](\frac {8x}{12}) = \frac {3200}{600}[/latex]
x = 8 months
3. If the ratio between the cost price and marked price of an article is 2:3. If the selling price of that article is Rs 1920 and the shopkeeper gave two successive discounts of 20% on the marked price. Find the loss during this transaction.
Answer - Option A
Explanation -
The ratio between the cost price and marked price of an article is 2:3
Let the cost price = 2x & marked price = 3x
Two consecutive discounts of 20% are given.
So, one cummulative discount for two discounts of 20%
20% + 20% - [latex]\frac {20 \times 20}{100}[/latex]% = 36%
Selling price = 1920 Rs
Hence,
[latex] 3x \times (\frac {64}{100}) = 1920[/latex]
x = 1000
So, Cost price = 2000 Rs & marked price = 3000 Rs
Loss = (Selling price - Cost price) = 1920 - 2000 = 80 Rs
4. Rs 18000 is invested in scheme ‘A’ by ram which offers 15% p.a. at simple interest and Rs 15000 in scheme ‘B’ which offers 18% p.a at compound interest. Find the difference between the interests earn from these two schemes after two years?
A. 396
B. 456
C. 486
D. 482
Answer - Option D
Explanation -
SI in scheme A = [latex]\frac {18000 \times 2 \times 15}{100} = 5400[/latex]
CI in scheme B = 15000 [latex]((\frac {118}{100} - \frac {118}{100}) - 1)[/latex] = 5886
Required difference = 5886 – 5400 = 486
So, option (D) is the correct answer.
5. The cost of a precious stone varies as the cube of its weight. A certain precious stone broke into three pieces whose weighs are in the ratio 1 : 2 : 3, as a result of which its cost reduces by 80280. What was the cost of the stone before breaking?
A. 56236
B. 96336
C. 85236
D. 76236
Answer - Option B
Explanation -
let the weights be x 2x and 3x grams
Previously, the weight of the stone was x + 2x +3x = 6x gms
Cost of the stone before breaking = [latex]k{(6x)}^{3} = 216k{x}^{3}[/latex]
Cost the stone after breaking = [latex]k [{x}^{3} + {(2x)}^{3} + {(3x)}^{3}] = 36k{x}^{3}[/latex]
Now, [latex]216k{x}^{3} – 36k{x}^{3} = 80280[/latex]
K[latex]{x}^{3} = \frac {80280}{180}[/latex]
216k[latex]{x}^{3} = \frac {80280}{180} \times [/latex] 216 = 96336