Four fifth of a number is more than three fourth of the number by 4. Find the number

Let the number be n.

Four fifths of the number is 4n/5.

Three fourths of the number is 3n/4.

Four fifths of a number is more than three fourths of the number by 4.

4n/5 = 3n/4 + 4

20 * 4n/5 = 20 * 3n/4 + 20 * 4

16n = 15n + 80

n = 80

Let's check.

4/5 of 80 = 4/5 * 80 = 64

3/4 of 80 = 3/4 * 80 = 60

64 is indeed 4 more than 60 showing that 4/5 of 80 is 4 more than 3/4 of 80, so 80 is correct.

Answer: 80

Let the unknown number be x then given,

(4/5) x - (3/4) x = 4

(16x - 15x) / 20 = 4

x/20 = 4

x=80