Question
A box contains (x + 3) black balls, 6 yellow balls, and
5 orange balls. If two balls are selected at random and the probability of selecting two orange balls is 10/153, what is the difference between the number of black balls and orange balls?Solution
5C2 / (x + 14) C2= 10/153 [(5 * 4) / (1 * 2)] / [(x + 14) (x + 13) / (1 * 2)] = 10/153 (2 * 153) = x2 + 14x + 13x + 182 306 = x2 + 27x + 182 x2 + 27x - 124 = 0 x2 + 31x – 4x – 124 = 0 X(x + 31) – 4(x + 31) = 0 (x – 4) (x + 31) = 0 x = 4, -31 (negative value will be eliminated) Required difference = 7 – 5 = 2 balls
?% of (168 ÷ 8 × 20) = 126
20% of 1500 – 75% of 200 = 125% of ?
Find the value of 16 X [(8 - 5) of 12 ÷ 4].
√196 + (0.25 × 144) + 19 = ? + 72
22 * 6 + 45% of 90 + 65% of 180 = ?
52% of 400 + √(?) = 60% of 600 - 25% of 400
(25 × 12 + 30 × 8 – 22 × 10) = ?
What will come in the place of question mark (?) in the given expression?
(240% of 175 ÷ √16) X 6 + 80% of 400 = ?3 + 179 + 42
What will come in the place of question mark (?) in the given expression?
(144 × 16 ÷ 12) × 6 = ?
808 ÷ (128)1/7 + 482 = 4 × ? + 846
