Question

5/7of 4/15 of a number is 8 more than of 2/5 of 4/9 of the same number. What is half of that number?​

Answer 1

Let the number be n. Then, according to the question the equation formed is —

415×57×n—49×25×n=8

(Because of means multiplication)

⟹4×5×n15×7—4×2×n9×5=8

⟹20n105—8n45=8

⟹4n21—8n45=8

Now 21=3×7 and 45=32×5 . Thus the LCM of 21 and 45 is

⟹32×5×7=315

Now solving the equation for n —

⟹4n21×315—8n45×315=8×315

⟹60n—56n=2520

⟹4n=2520

⟹n=630

Thus the half of the number is 630 ÷ 2 = 315