If r = 3s, s = 5t, t = 2u, and u ≠ 0, what is the value of rst/u^3

Question

If r = 3s, s = 5t, t = 2u, and u ≠ 0, what is the value of  \frac{rst}{u^3}  ?

A. 30

B. 60

C. 150

D. 300

E. 600

KSBGC · Answer

r = 3s = 3 * 10 u = 30 u

s = 5t = 5 * 2u = 10 u

t = 2u.

Question : \frac{rst}{u^3}  =  \frac{30u*10u*2u}{u*u*u}  = 600.

The best answer is E.

Note: As u is the denominator convert all the items in terms of u.

HasnainAfxal · Answer

convert all the right hand side of all equation into variable 'u'
as  t=2u 
so  s=5(2u)=10u 
 r=3(10u)=30u

so expression is:
 \frac{rst}{u^3}=\frac{30u*10u*2u}{u^3} 
 \frac{600u^3}{u^3}

600

Abhishek009 · Answer

r = 3*5(2u) =30u

s = 5(2u) = 10u

t = 2u

So,  \frac{rst}{u^3} = \frac{30u*10u*2u}{u^3}= 600 ; Answer must be (E)

Mo2men · Answer

Let  u=1   , therefore  t=2  &  s=10  &  r=30

\frac{rst}{u^3} =600

Answer E

Prep Toolkit