Question
The average age of a group of students in a school is 14
years. If 20% of them have an average age of 12 years and 40% have an average age of 16 years, then the rest students have an average age ofSolution
Let the total number of students be 100 So sum of the age of total students = 100 x 14 = 1400 20% of the students have average of 12 = 20% of 100 x 12 = 240 40% of the students have average of 16 = 40% of 100 x 16 = 640 Average of rest of the students = 100% - 60% = 40% Required average = (1400 – 240 – 640)/40 = 13 years Alternate method:
? = 460.24 + 1057.97 – 14.992 Â
30.05% of 149.97 + ? X 8.88 = (39.95 + 12.012 - 13.0322)2Â
? = ((64.13 - 34.97) + 16.89) x 1.98
15.99% of 549.99 ÷ 11.17 = ? ÷ 20.15
If cosec (2A + B) = (2/√3) and cosec (A + B) = √2, find the value of (4A - B) .
A bag contains 25 white and some black balls. If the probability of drawing a black ball from the bag is thrice that of drawing a white ball, fin...
194.95 + 3.98 × 64.99 - ? = (10.99 + 9.02)2
24.11 × 5.98 + 25.03 × 3.12 – 34.99 + 96.9 × 5.02 =?
30.05% of 1279.98 - ? x 4.06 = 8.082
1224.86% of √6399.98 = (399.99/4.99)% of (? ÷ 6.91 + 39.87)Â