Question
In a group, 2 people with average weight 55 kg leave,
and the average drops by 1 kg. If 3 people of average weight 56 kg leave, average drops by 2 kg. Find original number of people.Solution
ATQ,
mn - 110 = (n - 2)(m - 1)
→ mn - 110 = mn - n - 2m + 2
→ n + 2m = 112 -------- (i)
mn - 168 = (n - 3)(m - 2)
→ mn - 168 = mn - 2n - 3m + 6
→ 2n + 3m = 174 -------- (ii)
Multiply (i) by 2: 2n + 4m = 224
Subtract (ii):
2n + 4m - 2n - 3m = 224 - 174
→ m = 50
→ n = 112 - 2×50 = 12
Hence, answer is 12 people
What value should come in place of (?) question mark in the given expression.
17 × 15 − 96 ÷ 8 + 6² = ?
Evaluate: 144 ÷ 12 × 6 + 35 − 4²
What will come in the place of question mark (?) in the given expression?
21 × 18 + ? – 19 × 15 = 25 × 24
2916 ÷ 54 = ? + 27
√324 + √484 + 63 = ?2
What will come in the place of question mark (?) in the given expression?
{(2/15) + (12/25)} of 375 + 190 = ?% of 375
- What will come in place of the question mark (?) in the following questions?
100−[20+4×5]=? (72 × 52 + 1555 )/(79+60) = 2000 ÷ ?
72 × 2 = ? + 104 – 14
672 ÷ 28 × 24 + 363 – 309 =?
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