Question

15 upon 4 divided by 7 upon 8 multiply 25 upon 6 multiply 28 upon 15​

Answer 1

do you mean

$\frac{15}{4} \div \frac{7}{8} \times \frac{25}{6} \times \frac{28}{15}$

if yes then,

by BODMAS formula,

$= \frac{15}{4} \times \frac{8}{7} \times \frac{25}{6} \times \frac{28}{15}$

we can resiprocal a fraction to multiply simply instead of dividing

so,

$\frac{84000}{2520} = \frac{700}{21}$