The average weight of P, Q and R is 45 kg. If the average weight of P and Q be 36.5 kg and that of Q and R be 52 kg, then what is the weight (in kgs) of Q?
Let weights of P,Q and R be $$p,q,r$$ kg respectively.
Average weight of P, Q and RÂ = 45 kg
=> Sum of weights of P,Q and R = $$(p+q+r)=3\times45=135$$ kg -----------(i)
Average weight of P and Q = 36.5 kg
=> Sum of weights of P and Q = $$(p+q)=2\times36.5=73$$ kg ----------(ii)
Similarly, sum of weights of Q and R = $$(q+r)=2\times52=104$$ kg -----------(iii)
Adding equations (ii) and (iii),
=> $$p+2q+r=73+104=177$$ -----------(iv)
Subtracting equation (i) from (iv),Â
=> $$q=177-135=42$$ kg
=> Ans - (A)
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