Population after 2 yr
= P (1 + R/100)²
= 250000 (1 + 2/100)²

Correct Option: D

Population after 2 yr
= P (1 + R/100)²
= 250000 (1 + 2/100)²
⇒ 250000 x (51/50) x (51/50) = 260100
∴ Growth = 260100 - 250000 = 10100

Let the number of boys = B
and number of girls = G
Then, 10% of B = 1/4 of G

Correct Option: B

Let the number of boys = B
and number of girls = G
Then, 10% of B = 1/4 of G
⇒ B/10 = G/4
⇒ B/G = 10/4 = 5/2
⇒ B : G = 5 : 2

In such case, there is always decrease.
Given that, a = (common increase or decreased) = 7%

According to the formula,
Decreased Percentage = a²/100 %

Correct Option: D

In such case, there is always decrease.
Given that, a = (common increase or decreased) = 7%

According to the formula,
Decreased Percentage = a²/100 %
= 7²/100 %
= 0.49%

Let 1st number be M and 2nd number be M.
According to the question,
48% of M = 60% N
⇒ (M x 48)/100 = (N x 60)/100

Correct Option: C

Let 1st number be M and 2nd number be M.
According to the question,
48% of M = 60% N
⇒ (M x 48)/100 = (N x 60)/100
⇒ M/N = (60/100) x (100/48) = 5/4
∴ M : N = 5 : 4

Let the positive number be N.

According to the question
N x (15+ 20)% = 126
⇒ N x 35 = 126 x 100

Correct Option: C

Let the positive number be N.

According to the question
N x (15+ 20)% = 126
⇒ N x 35 = 126 x 100
∴ N = 12600/35 = 360
So, one-third of the number = 360/3 = 120