15. A sum when reckoned at 7% per annum amounts to 3920 in 3 years. Find the sum.
2
16. A sum of money put at 11% per annum amounts to 4491 in 2 years 3 months. What will it
x amount to in 3 years at the same rate?
17. A sum of money invested at 8% per annum amounts to 12122 in 2 years . What will it. plese send photo
Answers
Answer:
15. Rate of interest = 7% p.a.
Amts to = 3920
Time = 3yrs.
If it is simple interest then,
Si = p*r*t/100; and Amt.= Si + p
Therefore, ATQ.
3920 = (p*7*3/100) + p
=⟩ 3920 = 21p/100 + p
= 121p/100
=⟩ 3920 * 100 / 121 = p
=⟩ 3,239.66 = p
Therefore sum or p = 3,240 (Ans)
16. Rate of interest = 11% p.a.
Amts. to = 4491
Time = 2yrs and 3months
= 2 whole and 1/4 yrs or 9/4 yrs.
If it is simple interest then,
Si = p*r*t/100; and Amt.= Si + p
Therefore, ATQ.
4491 = (p*11*9/4)/100 + p
=⟩ 4491 = 99p/400 + p
= 499p/400
=⟩ 4491 * 400 / 499 = p
=⟩ 3600 = p
Therefore sum (x) or p = 3600
Now,
Rate of interest = 11% p.a.
Sum or principal (p) = 3600
Time = 3yrs
Si = p*r*t/100
Si = 3600 * 11 * 3 / 100
= 1188
Amt = Si + p
= 1188 + 3600
= 4788 (Ans)
17. Rate of interest = 8% p.a.
Amts. to = 12122
Time = 2yrs
If it is simple interest then,
Si = p*r*t/100; and Amt.= Si + p
Therefore, ATQ.
12122 = p*8*2/100 + p
=⟩ 12122 = 116p / 100
=⟩ 12122 * 100 / 100 = p
=⟩ 20,122.52 = p or 20,123 = p (Ans)
GUESS YOU DON'T NEED PHOTO ANY MORE, CHEERS!!