5. [tex]\(\frac{5}{7}\)[/tex] of a number [tex]\(X\)[/tex] is equal to [tex]\(\frac{4}{5}\)[/tex] of another number [tex]\(Y\)[/tex]. What is the value of the number [tex]\(X\)[/tex] if [tex]\(Y = 75\)[/tex]?

(a) 64
(b) 72
(c) 84
(d) 96



Answer :

To find the value of the number [tex]\(X\)[/tex] given that [tex]\(\frac{5}{7}\)[/tex] of [tex]\(X\)[/tex] is equal to [tex]\(\frac{4}{5}\)[/tex] of another number [tex]\(Y\)[/tex] and [tex]\(Y = 75\)[/tex], we can follow these steps:

1. Write the equation based on the given relationship:
[tex]\[ \frac{5}{7} X = \frac{4}{5} Y \][/tex]

2. Substitute [tex]\(Y = 75\)[/tex] into the equation:
[tex]\[ \frac{5}{7} X = \frac{4}{5} \cdot 75 \][/tex]

3. Calculate [tex]\(\frac{4}{5} \cdot 75\)[/tex]:
[tex]\[ \frac{4}{5} \cdot 75 = 4 \cdot 15 = 60 \][/tex]

4. So, the equation simplifies to:
[tex]\[ \frac{5}{7} X = 60 \][/tex]

5. Solve for [tex]\(X\)[/tex] by isolating [tex]\(X\)[/tex]:
[tex]\[ X = 60 \cdot \frac{7}{5} \][/tex]

6. Calculate [tex]\(60 \cdot \frac{7}{5}\)[/tex]:
[tex]\[ 60 \cdot \frac{7}{5} = 60 \cdot 1.4 = 84 \][/tex]

So, the value of the number [tex]\(X\)[/tex] is [tex]\(\boxed{84}\)[/tex].