Advertisements
Advertisements
Question
Rajiv obtained 70 and 75 marks in first two unit tests. Find the minimum marks he should get in the third test to have an average of at least 60 marks.
Solution
Let x1, x2, x3 denote the marks in 1st, 2nd, and 3rd unit tests respectively.
Then `("x"_1+"x"_2+"x"_3)/3≥60`
∴ `(70+75+"x"_3)/3≥60`
∴ 145 + x3 ≥ 3(60)
Subtracting 145 from both sides, we get
x ≥ 180 – 145
∴ x ≥ 35
Rajiv must obtain minimum 35 marks to maintain average of at least 60 marks.
APPEARS IN
RELATED QUESTIONS
Write the inequation that represent the interval and state whether the interval is bounded or unbounded.
[−4, 7/3]
Write the inequation that represent the interval and state whether the interval is bounded or unbounded.
[0, 0.9]
Write the inequation that represent the interval and state whether the interval is bounded or unbounded.
`(- ∞,∞)`
Write the inequation that represent the interval and state whether the interval is bounded or unbounded.
`[5, ∞]`
Write the inequation that represent the interval and state whether the interval is bounded or unbounded.
(– 11, – 2)
Write the inequation that represent the interval and state whether the interval is bounded or unbounded.
`(-∞, 3)`
Solve the inequation:
5x + 7 > 4 – 2x
Find all pairs of consecutive odd positive integers both of which are smaller than 10 such that their sum is more than 11.
Find all pairs of consecutive even positive integers, both of which are larger than 5 such that their sum is less than 23.
The longest side of a triangle is twice the shortest side and the third side is 2cm longer than the shortest side. If the perimeter of the triangle is more than 166 cm then find the minimum length of the shortest side.
