P,Q and R together earn Rs.1890 in 9 days. P and R can earn Rs.600 in 5 days. Q and R in 7 days can earn Rs.910. How much amount does R can earn per day?  Choose the correct option:
A) s.40
B) s.70
C) s.90
D) s.100
E) s.120
Explanation :   s.40mount Earned by P,Q and R in 1 day = 1890/9= 
<gadget id="calculator">1890/9</gadget>
<output>210</output>
210 ---(1)   s.40mount Earned by P and R in 1 day= 600/5= 
<gadget id="calculator">600/5</gadget>
<output>120</output>
120	---(2)   s.40mount Earned by Q and R in 1 day= 910/7= 
<gadget id="calculator">910/7</gadget>
<output>130</output>
130	---(3)   (2)+(3)-(1)=&gt; s.40mount Earned by P , Q and 2R in 1 day   - s.40mount Earned by P,Q and R in 1 day = 120+130-210= 
<gadget id="calculator">120+130-210</gadget>
<output>40</output>
40=&gt;s.40mount Earned by R in 1 day = 40   s.40nswer : Option s.40
<result>A</result>
P,Q and R together earn Rs.1890 in 9 days. P and R can earn Rs.600 in 5 days. Q and R in 7 days can earn Rs.910. How much amount does R can earn per day?