जॉइन Examsbookउत्तर : 4. "72"
The average number of visitors of a library in the first 4 days of a week was 58. The average for the 2nd, 3rd, 4th and 5th days was 60.If the number of visitors on the 1st and 5th days were in the ratio 8 : 9. Then what is the number of visitors on the 5th day of the library ?5
प्र: The average number of visitors of a library in the first 4 days of a week was 58. The average for the 2nd, 3rd, 4th and 5th days was 60.If the number of visitors on the 1st and 5th days were in the ratio 8 : 9. Then what is the number of visitors on the 5th day of the library ?
- 154false
- 264false
- 368false
- 472true
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उत्तर : 4. "72"
व्याख्या :
Answer: D) 72 Explanation: If number of visitors on 1st, 2nd, 3rd, 4th & 5th day are k, l, m, n & o respectively, thenk + l + m + n = 58 x 4 = 232 ---- (i) & l + m + n + o = 60 x 4 = 240 ---- (ii)Subtracting (i) from (ii), we get o-k = 8 ---(iii)Given, k/o = 8/9 ----(iv)So from (iii) & (iv), we geta = 64, e = 72Therefore, number of visitors on 5th day is 72.