A tyre has two punctures. The first puncture alone would have made the tyre flat in 25 minutes, and 2nd puncture do the same tyre flat in 15 minutes.Both started their work, After 4 minutes the puncture 2 has mechanic close the leak.Then how many minutes 1st puncture required to flat the remaining air of the tyre?  Choose the correct answer
A) 5 minutes
B) 2 minutes
C) 3.25 minutes
D) 2.25 minutes
E) 1.72 minutes
First take LCM of (25,15) = 75; Total work = 75; 1st puncture make the tyre flat in one minutes = 75/25= 
<gadget id="calculator">75/25</gadget>
<output>3</output>
3 ; 2nd's puncture make the tyre flat in one minutes=75/15= 
<gadget id="calculator">75/15</gadget>
<output>5</output>
5 ; both can flat the tyre in= 3+5= 
<gadget id="calculator">3+5</gadget>
<output>8</output>
8 min; Total work completed in 4 min= 8*4= 
<gadget id="calculator">8*4</gadget>
<output>32</output>
32; remaining work is= 75 - 32= 
<gadget id="calculator">75 - 32</gadget>
<output>43</output>
43; remaining work completed by 1st puncture in= 43/25= 
<gadget id="calculator">43/25</gadget>
<output>43/25 = around 1.72</output>
1.72 min.   Answer= 1.72 minutes
<result>E</result>
A tyre has two punctures. The first puncture alone would have made the tyre flat in 25 minutes, and 2nd puncture do the same tyre flat in 15 minutes.Both started their work, After 4 minutes the puncture 2 has mechanic close the leak.Then how many minutes 1st puncture required to flat the remaining air of the tyre?