Q.1.The difference in simple interest and compound interest on a certain sum of money in 2 years at 10 % p.a. is Rs. 50. The sum is
a) Rs. 10000 b) Rs. 6000 c) Rs. 5000 d) Rs. 2000 e) None of these Sol : Option C Q.2. The difference in simple interest and compound interest on a certain sum of money in 2 years at 18 % p.a. is Rs. 162. The sum is
a) Rs. 4000 b) Rs. 5200 c) Rs. 4250 d) Rs. 5000 e) None of these Sol : Option D Q.3. The compound interest on a certain sum of money for 2 years is Rs. 208 and the simple interest for the same time at the same rate is Rs. 200. Find the rate %.
a) 5 % b) 6 % c) 7 % d) 4 % e) 8 % Sol : Option E Therefore, Rs.8 Gap is because of the interest of 1st year interest. Rs. 8 is interest on Rs. 100, R= (8x100)/(100x1) % ,R = 8% Q.4.The difference between compound interest and simple interest on a certain sum for 2 years at 10 % is Rs. 25. The sum is
a) Rs. 1200 b) Rs. 2500 c) Rs. 750 d) Rs. 1250 e) Rs. 2000 Sol : Option B Q.5.The simple interest on a certain sum for 3 years in Rs. 225 and the compound interest on the same sum for 2 years is Rs. 165. Find the rate percent per annum.
a) 20 % b) 2.5 % c) 5 % d) 15 % e) 7.5% Sol : Option A Q.6.The simple interest on a sum of money for 2 years is Rs. 150 and the compound interest on the same sum at same rate for 2 years is Rs. 155. The rate % p.a. is
a) 16 % b) 20/3 % c) 12 % d) 10 % e) None of these Sol : Option B Q7.Mihir’s capital is 5/4 times more than Tulsi’s capital. Tulsi invested her capital at 50 % per annum for 3 years (compounded annually). At what rate % p.a. simple interest should Mihir invest his capital so that after 3 years, they both have the same amount of capital?
a) 20/3 % b) 10 % c) 50/3 % d) 1.728 % e) None of these Sol : Option C Q8.The difference in simple interest and compound interest on a certain sum of money in 3 years at 10 % p.a. is Rs. 372. The sum is
a) Rs. 8000 b) Rs.9000 c) Rs. 10000 d) Rs. 12000 e) None of these Sol : Option D Therefore, the principle will also be 12 times of Rs. 1000 i.e. Rs. 12000. Q9.Sahil’s capital is 1/6 times more than Chaya’s capital. Chaya invested her capital at 20 % per annum for 2 years (compounded annually). At what rate % p.a. simple interest should Sahil invest his capital so that after 2 years, they both have the same amount of capital?
a) 10% b) 11 5/7% c) 20% d) 13 5/7% e) None of these Sol : Option B Q10.The difference in simple interest and compound interest on a certain sum of money in 3 years at 20 % p.a. is Rs. 640. The sum is
a) Rs. 5000 b) Rs. 8500 c) Rs. 8250 d) Rs. 6000 e) None of these Sol : Option A Therefore, the principle will also be 5 times of Rs. 1000 i.e. Rs. 5000. P = Rs. 9430R = 5% T = 10 years SI = `[ 9430 xx 5 xx 10 ]/100` = Rs. 4715 Let sum = X CI = AP `4715 = "X"[ 1 + "R"/100 ]^"T" - "X"` `4715 = "X"[ 1 + 5/100 ]^2 - "X"` `4715 = "X"|(21/20)^2 - 1|` `4715 = "X"([ 441 - 400]/400)` `"X" = [ 4715 xx 400]/41` = Rs. 46,000 Thus principal from = Rs. 46,000 |