Question

Mark the correct alternative in the following question:

Two-third of a number is greater than one-third of the number by 5. The number is

(a) 10 (b) 5 (c) 15 (d) 12

Answer 1

$$\begin{gathered} \mathrm{Let}\mathrm{the}\mathrm{number}\mathrm{be}x. \\ \mathrm{As},\mathrm{two}-\mathrm{third}\mathrm{of}\mathrm{a}\mathrm{number}\mathrm{is}\mathrm{greater}\mathrm{than}\mathrm{one}-\mathrm{third}\mathrm{of}\mathrm{the}\mathrm{number}\mathrm{by}5. \\ \Rightarrow \frac{2}{3}x-\frac{1}{3}x=5 \\ \Rightarrow \frac{2x-x}{3}=5 \\ \Rightarrow \frac{x}{3}=5 \\ \Rightarrow x=5\times 3 \\ \therefore x=15 \end{gathered}$$

So, the number is 15.

Hence, the correct alternative is option (c).