Question

i need to know how to solve 13,14,15queston

Answer 1

13)Principal =x. Rate=10%. Time=3 years.
Simple Interest= Principal×Rate×Time/100=x×10×3/100=0.3x.
Compound Interest can be calculated by
$c.i. = x {(1 + 0.01r)}^{t} - x$
where r is the rate and time is t.
c.i.= x(1+0.01(10))^3-x = x(1+0.1)^3-x=1.331x-x=0.331x.
Difference between simple Interest and compound Interest=31=0.331x-0.3x=0.031x . x=31/31/1000= ₹1000 .
14) find Least Common Multiple of 8,12,20 and 25.
2 |8,12,20,25
2 |4,6,10,25
2 |2,3,5,25
5 |1,3,5,25
|1,3,1,5 L.C.M=2×2×2×5×3×5=600.Now they said that when divided by any of the above numbers it leaves a remainder 5 so Answer can be 605.