Problem: A novelist earned Tk. 1,00,000 from royalties on her book. She paid 20% income tax or the royalties. She invested Tk. 50,000 at one rate and the rest at a rate that was 1% lower earning 6,100 taka annual interest on the two investments. What was the lower rate?
View all: AGRANI BANK LTD (OFFICER-CACH) WRITTEN QUESTION (MATH) SOLVE | 2018
Correct Answer: 7%
Explanation:
here. Earned royalties = 1,00,000 TK
Remaining royalties after tax = 1.00.000 – ( 1,00,000 x 20%) = 80,000 TK
Invested at higher rate = 50.000 TK
so, Invested at lower rate = 80.000 – 50,000 = 30,000 TK
Let. Higher rate be = x%
Lower rate be = (x-1)%
According to the question
(50,000× x%× x%×1)+{(30,000 × (x-1)%×1)% ×1)} = 6,100
=> 50,000 $\frac{x}{100} $ + 30,000 $\frac{x-1}{100}$ = 6,100
=> 500x + 300(x -1) = 6,100=> 500x + 300x -300 = 6,100=> 800x = 6,100 + 300
so, x = 8
so, Higher rate = 8%
So lower rate = 8 -1 = 7%
