Question

total amount of Rs 40000 is invested. a part of it is invested at 4% and rest at 6% p.a. interest of all is Rs 2130. how much is each investment.

Answer 1

Answer:

It's very easy

Step-by-step explanation:

Let one part =x

∴ Other part =40000−x

For Part 1

r=10%,P=x

T=t (Let)

∴S.I=

100

PRT

​

=

100

x×10×t

​

=

10

xt

​

For Part 2

P=(40000−x)

R=6%

T=t

∴S.I=

100

(40000−x)×6×t

​

=

100

(40000−x)6t

​

ATP,

10

xt

​

+

100

(40000−x)6t

​

=

100

40000×7.5×t

​

⇒

10

xt

​

+

100

(40000−x)6t

​

=3000t×100

⇒10x+(40000−x)6=300000

⇒10x−6x+240000=300000

⇒4x=60000

⇒x=15,000

∴ Other part =40000−x=25,000

∴ Part 1: Part 2 =15,000:25000

                            =3:5