Suppose $P_1, \, P_2$ are principles, $T_1, \, T_2$ are times periods and $R_1,\, R_2$ are rates of interest in two cases. If $P_1\,:\, P_2\,=\, 2:\,3,\, T_1\,:\, T_2\, =\, 3\, :\, 5$ and $R_1\,:\,R_2\,=\, 5\, :\, 8$ then find the percent with which SI second case $(I_2)$ is more than the S.I. in I case $(I_1)$ ?

Using the simple interest formula where Interest equals the product of Principal, Rate, and Time, the ratio of the interests is I1 : I2 = (2 x 3 x 5) : (3 x 5 x 8) = 30 : 120, or 1 : 4. The second case interest I2 is therefore 4 times I1. To find by what percentage I2 is more than I1, calculate the difference divided by I1 and multiplied by 100, yielding (4 - 1) / 1 x 100 = 300 percent.

• Thanks
• Wrong explanation