Question
The average age of a group of 10 friends is 27 years. If
one friend leaves the group, the average becomes 25years. Find the age of the friend who left the group.Solution
ATQ, The sum of ages of 10 friends is 270 (since the average is 27 years). If one friend leaves, there are 9 friends left, and the new average becomes 25 years. The new sum of ages is 225. The age of the friend who left is the difference between the original sum and the new sum = 270 - 225 = 45. So, the age of the friend who left the group is 45 years.
What value should come in place of (?) in the given expression.
450 ÷ 9 + 75% of 160 − 64 ÷ 4 = ?
2/5 of 3/4 of 7/9 of 14400 = ?
7/3 of 4/5 of 15/56 of ? = 83
[564 + 32 of 18 × 9 ÷ 12 + 162 ] ÷ 4 = ?
What should come in place of (?) question mark in the given expression.
(25% of 320) + (3/8 of 400) − 30 = ?
45% of 360 - 160 + ? = √324
187 ÷ 5 ÷ 0.4 = ? – 24 × 2.4
Find the simplified value of the following expression:
[{12 + (13 × 4 ÷ 2 ÷ 2) × 5 – 8} + 13 of 8]
18 × 15 + 86 – 58 =? + 38
√(24²+285-8²-172) = ?²
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