type 3 money multiples in ‘n’ years Practice Questions Answers Test with Solutions & More Shortcuts

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: (c)

Let principal be Rs. x.

Amount = Rs.2x

Interest = Rs.(2x - x) = Rs.x

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

= ${x × 100}/{x × 8} = 25/2$

= 12$1/2%$ per annum

Answer: (d)

Let the principal be x.

Case-I

$2x = {x × R × 15}/100$

R = ${2 × 100}/15 = 40/3%$

Case-II

SI = 4x

$4x = {x × 40 × T}/300$

T = ${4 × 300}/40 = 30$ years

Using Rule 3,

R = ${(3 - 1)}/15 × 100%$

= $2/15 × 100%$

= $2/3 × 20% = 40/3%$

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

= ${(5 - 1)}/{40/3} × 100$ = 30 years.