Question

Anoop borrowed Rs. 800 at 6 % p.a. & Rs. 1200 at 7 % p.a. for the same duration. He had to pay Rs. 1584 in all as interest. Find the time period.

Answer 1

Given:

Interest at 1st rate for 1 year:

$\implies$ 800 × (6 × 1) / 100

$\implies$ 800 × 6 / 100

$\implies$ 4800 / 100

$\implies$ Rs. 48

And:

Interest for 1 year at 2nd rate:

$\implies$ 1200 × (7 × 1) / 100

$\implies$ 1200 × 7 / 100

$\implies$ 8400 / 100

$\implies$ Rs. 84

Therefore:

Total interest for 1 year:

$\implies$ Rs. 48 + Rs. 84

$\implies$ Rs. 132

Hence:

The required time:

$\implies$ 1584 / 132

$\implies$ 12 years

Final answer: 12 years

Answer 2

Answer:

Step-by-step explanation:

total interest=1584

total interest=i1+i2

                      =p1*t1*r1/100+p2*t1*r2/100

p1=800

r1=6

p2=1200

r2=7

total interest=800*6*t/100+1200*7*t /100

1584*100=4800t+8400t

158400= 13200t

t=12