type 3 money multiples in ‘n’ years Section-Wise Topic Notes With Detailed Explanation And Example Questions

Answer: (d)

TIme = ${SI × 100}/\text"Principal × Rate"$

= ${x × 100}/{x × 25/4}$ = 16 years

Using Rule 3,

T = ${(n - 1)}/{R%} years$

= ${(2 - 1)}/{25/4} × 100$ years = 16 years.

Answer: (b)

According to the question,

If principal be Rs. x, then

S.I. = Rs. x

Time = ${SI × 100}/\text"Principal × Rate"$

= ${x × 100}/{x × 25/4} = 400/25$ = 16 years

Using Rule 3,

T = ${(n - 1)}/R × 100%$

= ${2 - 1}/{25/4} × 100$

= $400/25$ = 16 years.

Answer: (a)

Principal = Rs.x

Amount = Rs.2x

Interest = 2x - x = Rs.x

Rate = ${SI × 100}/\text"Principal × Time"$

= ${x × 100}/{x × 8} = 25/2$ = 12.5 % per annum

Using Rule 3,

R % = ${(n - 1)}/T × 100%$

= ${(2 - 1)}/8 × 100%$ = 12.5%

Answer: (d)

If the principal be Rs.100 then S.I. = Rs.100.

Time = ${SI × 100}/\text"Principal × Rate"$

= ${100 × 100}/{100 × 12} = 25/3$ years

= 8 years 4 months

Using Rule 3,

T = ${(n - 1)}/R × 100%$

= ${(2 - 1)}/12 × 100%$

= $100/12 = 25/3$ years.

= 8$1/3$ years

= 8 years, 4 months.

Answer: (c)

If the principal be x, the amount = 2x

SI = x

Time = ${SI × 100}/\text"Principal × Rate"$

= ${x × 100}/{x × 15} = 20/3 = 6{2}/3$ years

Using Rule 3,

T = ${(n - 1)}/R × 100%$

= $({2 - 1}/15) × 100$

= $100/15 = 20/3$ Years

= 6$2/3$ years

Answer: (a)

Case I,

Principal = Rs.x

Interest = Rs.x

Time = 6 years

Rate = ${Interest × 100}/\text"Principal × Time"$

= ${x × 100}/{x × 16} = 50/3%$ per annum

Case II,

Interest = ${x × 12 × 50}/{100 × 3}$ = Rs.2x

i.e., Amount is thrice the principal.