Given. T₁ = 2 yr and T₂ = 4 yr,
P₁ = 600, P₂ = 150.

According to the question,
SI₁ + SI₂ = 80
[(600 x R x 2)/100] + [(150 x R x 4)/100] = 80

Correct Option: D

Given. T₁ = 2 yr and T₂ = 4 yr,
P₁ = 600, P₂ = 150.

According to the question,
SI₁ + SI₂ = 80
[(600 x R x 2)/100] + [(150 x R x 4)/100] = 80
⇒ 120R + 60R = 800
⇒ 180R = 800
∴ R = 800/180 = 80/18 = 40/9
= 4⁴/₉%

Let the principal be P.
Then, according to the question,
(P x T x T) / 100 = P/144 [∵ time and rate are equal

Correct Option: B

Let the principal be P.
Then, according to the question,
(P x T x T) / 100 = P/144 [∵ time and rate are equal]
⇒ T² = 100/144
∴ T = 10/12 = 5/6 %

Let principal = P, time = T and rate = T
According to the question,
(P x T x T) / 100 = P/16 [∵ time and rate are equal]

Correct Option: A

Let principal = P, time = T and rate = T
According to the question,
(P x T x T) / 100 = P/16 [∵ time and rate are equal]
⇒ T² = 100/16
or T = 10/4 = 5/2 = 2¹/₂ %

Let. principal = P
Given, SI = 55, Time T = 9 months = 9/12 yr,
Rate R = 3²/₃% = 11/3 %
∴ SI = (P x R x T) / 100
⇒ P = (100 x SI) / (R x T)

Correct Option: C

Let. principal = P
Given, SI = 55, Time T = 9 months = 9/12 yr,
Rate R = 3²/₃% = 11/3 %
∴ SI = (P x R x T) / 100
⇒ P = (100 x SI) / (R x T)
⇒ (55 x 100) / [(11 x 9) / (3 x 12)] = 2000
∴ Principal (P) = ₹ 2000

According to the question,
SI for 5 yr = ₹ 200
∴ Total SI for 10 yr = 200 + 600 = ₹ 800

Correct Option: C

According to the question,
SI for 5 yr = ₹ 200
∴ Total SI for 10 yr = 200 + 600 = ₹ 800
When principal is trebled, then SI for 5 yr will also be treble and hence
SI for next 5 yr will be ₹ (200 x 3) i.e., ₹ 600.