An Office used three types of envelopes: small,medium and large. They used 80 small envelopes. The no.of Medium envelopes used was 5 times, the no.of small envelopes plus 5/20 of the number of envelopes. The no.of.large envelopes was equals to the no.of small envelopes plus 5/20 of the no.of medium envelope. Altogether, How many envelope did they use? Choose the correct choice from the following answers: A) 950 B) 960 C) 972 D) 970 E) 980
Let the total no. of envelopes be x   No. of small envelopes = 80   No. of medium envelopes =5*80+5/20*x = 400+5/20*x   No. of large envelopes = 80 +5/20(400+5/20*x) = 180+25/400*x   Sum of small, medium and large envelopes = x   80 + 400+5/20*x + 180+25/400*x = x   660 + 5/16*x = x   11/16*x = 660   x = 960   ANSWER:960
<result>B</result>
An Office used three types of envelopes: small,medium and large. They used 80 small envelopes. The no.of Medium envelopes used was 5 times, the no.of small envelopes plus 5/20 of the number of envelopes. The no.of.large envelopes was equals to the no.of small envelopes plus 5/20 of the no.of medium envelope. Altogether, How many envelope did they use?