1ans is C)225
if r,s t are prime nos. and p,q,r are +ve integers such dat LCM of p,q is r2t4s2 then the no. of ordered pairs (p,q) is.....patha nahin...y nothin strikes my big head
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5 Answers
13yup it is 225
no. of ways p and q has r as a factor giving r2 as LCM
p having no r as factor
q having r2 as factor
p---->r
q----->r2
p----->r2
q----->r
p------>r2
q----->r
p------>r2
q----->r2
total 5 ways
simillarly for s we have 5 ways
for t
p q
no t t4
t t4
t2 t4
t3 t4
t4 t0,t,t2,t3t4
9 ways
total 5*5*9=225