A owes B Rs 1573, payable 3/2 year hence. Also B owes A Rs 1,444.50, payable 6 months hence. If they want to settle the account forthwith, keeping 14% as the rate of interest, then who should pay whom and how much?
Answer: D Let the present value of what A owes B be Rs x. Then, x + (x*14*3)/(2*100) = 1573 => x= Rs 1300 Let y be the present value of what B owes A => y + (y * 1/2 * 14/100) = Rs 1444.50 => y = Rs 1350 Hence, B must pay Rs 50 to A.
Q. No. 14:
Consider the following statements If a sum of money is lent at simple interest, then the I). Money gets doubled in 5 year if the rate of interest is 50/3 %. II). Money gets double in 5 year if the rate of interest in 20%. III). Money becomes four times in 10 year if it gets doubled in 5 year. Of these statements
Answer: B Let the sum of money lent be Rs P. Then, I). SI received after 5 year = (P*50*5)/(3*100) = 5P/6. Amount after 5 year = P + 5P/6 = 11P/6 Therefore, I is not correct II). SI after 5 year = (P*20*5)/100 = P Amount after 5 year = P+P = 2P Therefore, II is correct. III). Amount after 10 year at the rate of 20% => P + (P*20*10)/100 = P+2P = 3P (At 20% money gets doubled in 5 year) Therefore, III is not correct
Q. No. 15:
A finance company declares that, at a certain compound interest rate, a sum of money deposited by anyone will becomes 8 times in three years. If the same amount is deposited at the same compound rate of interest, then in how many years will it become 16 times?
Answer: A P + CI of 3 year = Rs 6560 P + CI of 4 year = Rs 7216 CI of 4th year = 7216 - 6560 = Rs 656. Compound interest on 4th year is the simple interest on the amount generated after 3 year, which is Rs 6560. => r = (656*100) / (6560*1) = 10%
Q. No. 17:
A certain sum is invested for certain time. It amounts to Rs 450 at 7% per annum. But when invested at 5% per annum, it amounts to Rs 350. The time is
Answer: A (450 - P) = (P*7*T)/100 => PT = (45000 - 100P)/7........(i) and (350 - P) = (P*5*T)/100 => PT = (35000-100P)/5.........(ii) On solving two equation we get P =100 and T = 50 year.
Q. No. 18:
A sum of money becomes five times at simple rate of 8% per annum. At what rate percent will it become seven fold?