70. A man has Rs. 10,000 to Invest. He invests
Rs. 4000 at 5% and Rs. 3500 at 4%. In order
to have a yearly Income of Rs. 500, he must
invest the remaining Rs. 2500 at what rate of
Interest?
(A) 6%
(B) 6.2%
(C) 6 3%
(D) 6.4%
Answers
Answer:
6.4℅
Step-by-step explanation:
given
- principle = ₹10000
- 1st investment = ₹4000 @ 5℅
- 2nd investment = ₹3500 @ 4℅
- total intrest = ₹500
- time = 1 year
now,
we know that
simple intrest = p*r*t/100
so,
intrest gained from 1st investment =>
=> 4000*5*1/100 = ₹200
&
intrest gained from 2nd investment =>
=> 3500*4*1/100 = ₹140
but given that total intrest = ₹500
so,
₹500 - (200+140) = 500 - 340 = ₹160
hence,
intrest on ₹2500 = ₹160
so,
rate of intrest = intrest×100 / principle × time
=> rate = 160 × 100 / 2500 × 1
=> rate = 6.4℅ (answer)
Answer:
Step-by-step explanation:
Solution:
Income from $ 4000 at 5 % in one year = $ 4000 of 5 %.
= $ 4000 × 5/100.
= $ 4000 × 0.05.
= $ 200.
Income from $ 3500 at 4 % in one year = $ 3500 of 4 %.
= $ 3500 × 4/100.
= $ 3500 × 0.04.
= $ 140.
Total income from 4000 at 5 % and 3500 at 4 % = $ 200 + $ 140 = $ 340.
Remaining income amount in order to have a yearly income of $ 500 = $ 500 - $ 340.
= $ 160.
Total invested amount = $ 4000 + $ 3500 = $7500.
Remaining invest amount = $ 10000 - $ 7500 = $ 2500.
We know that, Interest = Principal × Rate × Time
Interest = $ 160,
Principal = $ 2500,
Rate = r [we need to find the value of r],
Time = 1 year.
160 = 2500 × r × 1.
160 = 2500r
160/2500 = 2500r/2500 [divide both sides by 2500]
0.064 = r
r = 0.064
Change it to a percent by moving the decimal to the right two places r = 6.4 %
Therefore, he invested the remaining amount $ 2500 at 6.4 % in order to get $ 500 income every year.
Answer: (e)