Simple Interest Practice Test 4

Let the sum of money lent at 10% = x
Let the sum of money lent at 15% = y
So, his income = Rs 1,900

10

100

x+

15

100

y=1900
10x+15y=190000 ......(i)
If the rate of interest is interchanged, then he earns Rs 200 more. So,

15

100

x+

10

100

y=2100
15x+10y=210000 ......(ii)
Now solving equation (i) and (ii) we get,
y = 6,000Substituting the value of y in equation (i)
10x+(15×6,000)=1,90,000
10x=1,90,000−9,000
x=10,000
So, the total sum of money =x+y=10,000+6,000 = Rs 16,000
Rate of interest = 15%
SI=

16000×15×1

100

=2400
So, the amount is Rs 2,400.