type 2 increase or decrease in interest rate Section-Wise Topic Notes With Detailed Explanation And Example Questions

Answer: (b)

Using Rule 1,

Case I,

S.I. = 920 - 800 = Rs.120

Rate = ${\text"S.I." × 100}/\text" Principal × Time"$

= ${120 × 100}/{800 × 3}$ = 5% per annum

Case II,

Rate = 8% per annum

S.I. = ${800 × 8 × 3}/100$ = Rs.192

Amount = Principal + S.I.

= (800 + 192) = Rs.992

Answer: (b)

Let the sum = P and original rate = R% per annum.

Then, ${P × (R + 3) × 2}/100 - {P × R × 2}/100 = 72$

${P × 3 × 2}/100 = 72$

P = ${72 × 100}/{3 × 2}$ = Rs.1200

$P_1 = P, R_1 = R, T_1$ = 2

$P_2 = P, R_2 = R + 3, T_2$ = 2

S.I.= 72

72 = ${P × (R + 3) × 2 - P × R × 2}/100$

7200 = 6P

P = Rs.1200

Answer: (d)

If the capital after tax deduction be x, then

x × (4 - 3.75) % = 48

${x × 0.25}/100$ = 48

${x × 25}/10000$ = 48

$x/400$ = 48

x = 48 × 400 = Rs.19200

Required capital

= ${19200 × 100}/96$ = Rs.20000

Answer: (c)

Using Rule 1,

S.I. = Rs.(920 - 800) = Rs.120

Rate = ${\text"S.I." × 100}/\text" Principal × Time"$

= ${120 × 100}/{800 × 3}$ = 5% per annum

New rate = 8% per annum

S.I. = ${800 × 3 × 8}/100$ = Rs.192

Amount = (800 + 192) = Rs.992

Answer: (b)

Using Rule 1,

S.I. = 2352 - 2100 = Rs.252

Rate = ${\text"S.I." × 100}/\text" Principal × Time"$

= ${252 × 100}/{2100 × 2}$ = 6% per annum

New rate = 5%

S.I. = ${252 × 5}/6$ = Rs.210

Answer: (c)

If the sum lent be Rs. x, then

${x × 2.5 × 3}/100 = 540$

$x = {540 × 100}/{2.5 × 3}$ = Rs.7200

Using Rule 13,

$P_1 = P, R_1 = R, T_1$ = 3

$P_2 = P, R_2 = R + 2.5%, T_2$ = 3

S.I. = Rs.540

540 = ${P × (R + 2.5%) × 3 - P × R × 3}/100$

54000 = 7.5P

P = $540000/75$

P = Rs.7200