Ravi gave Rs 1200 on loan. Some amount he gave at 4% per annum simple interest and remaining at 5% per annum simple interest. After two years, he got Rs 100 as interest. Then the amount given at 4% and 5% per annum simple interest are, respectively

Answer: A Let the amount given at 4% per annum be Rs x Amount given at 5% per annum = Rs (1200 -x) Thus, (x*4*2)/100 + {(1200-x)*5*2}/100 = 110 => x= 500. Also, (1200 - x) = 1200 - 500 = 700.

Q. No. 8:

The difference between compound interest and the simple interest on a certain amount of money at 5% per annum for 2 year is Rs 15. ind the sum.

Answer: B Let the sum be of Rs 100. Then SI = (100*5*2)/100 = Rs 10 and CI = 100(1 + 5/100)^{2} -100 = 41/4 CI - SI = 41/4 - 10 = 1/4 If the difference is 1/4, the sum = 100 If the difference is Rs 15, then the sum = Rs 6,000

Q. No. 9:

Sumit lent some money to Mohit at 5% per annum simple interest. Mohit lent the entire amount to Birju on the same day at 17/2 % per annum. In this transaction, after a year Mohit earned a profit of Rs 350. Find the sum of money lent by Sumit to Mohit

Answer: B Let rate of interest be r% Then, 2520 / 2400 = (1 + r/100)^{4} / (1+r/100)^{3} => 63/60 = 1 + r/100 => r= 5%

Q. No. 11:

Two equal sums of money are lent at the same time at 8% and 7% per annum simple interest. The former is recovered 6 months earlier than the later and the amount in each case is Rs 2,560. The sum and the time for which the sums of money are lent out are

Answer: D Let each amount be Rs x and time be t years. Then, x + (t - 1/2) * 8/100 = x + (x*x*t*7)/100 => 2xt/25 - x/25 = 7xt/100 => xt/100 = x/25 => t = 4 years. First money was lent for 4 -1/2 = 3.5 year. Amount = x + (3.5*x*8)/100 = Rs 2560 => x = Rs 2000.

Q. No. 12:

Divide Rs 1586 in three parts in such a way that their amounts at the end of 2,3 and 4 years respectively, at 5% per annum simple interest be equal

Answer: C Let the three parts be Rs x, Rs y and Rs z. According to question x + (x*2*5)/100 = y + (y*3*5)/100 = z + (z*4*5)/100 => 1.1 x = 1.15 y = 1.2 z x : y : z = 276 : 264 : 253 Thus, x = 276/793 * 1586 = Rs 552 y= Rs 528 and z = Rs 506.