Question

The sum of three numbers is $98$. If the ratio of the first to second is $2:3$ and that of the second to the third is $5:8$, then the second number is:

Answer 1

Let the three parts be A, B, C. Then,
$A:B=2:3$ and $B:C=5:8=$ $(5\times \frac{3}{5}):(8\times \frac{3}{5})=3:\frac{24}{5}$
$=>A:B:C=2:3:$ $\frac{24}{5}$ $=10:15:24$
$=>B=$$(98\times \frac{15}{49})$$=30$