Question

vaibhav inherited Rs. 12000.00. He invested a part of it as 10% and the rest at 12%. His annual income from these investments is Rs 1280. How much he invested at rate of 12%?
Answer fully
and answer is rs.4000

Answer 1

let part invested at 12% be x
hence part invested at 10% is 12000-x

therefore 12/100x+10/100(12000-x)=1280
=>0.12x+0.1(12000-x)=1280
=>0.12x+1200-0.1x=1280
=>0.02x=80
=>x=80/0.02
=>x=4000

Answer 2

Answer:

Rs.4000

Step-by-step explanation:

Let the invested part at 12% be x

Hence the part invested at 10% is 12000-x

Therefore

12/100 x + 10/100 (12000-x) =1280

0.12x+0.1(12000-x)=1280

0.12x+1200-0.1x=1280

0.12x-0.1x=1280-1200

0.02x=80

x=80/0.02

x=8000/2

x=4000

Answer: Rs 4000