PROBABILITY
a). Find the probability that a number selected at random from the numbers 30, 31, 32, 33, ......, 60 is (i) a prime number (ii) a multiple of 6.
7/31 and 6/31
In the below figure AT is a tangent to the circle with centre O such that OT = 4 cm and OTA = 30°. Then AT is equal to
2RT 3
If Sn, the sum of first n terms of an A.P. is given by Sn = 3x2 – 4x, find the nth term.
6N -7
From a bag containing yellow, red and green balls, the probability of drawing a yellow or red ball is equal to that of drawing a green ball. The probability of drawing a green ball from the bag is
1/2
In figure if O is centre of a circle, PQ is a chord and the tangent PR at P makes an angle of 50° with PQ, then POQ is equal to
100
In an AP of 50 terms, the sum of first 10 terms is 210 and the sum of last 15 terms is 2565. Find the A.P.
3,7,11,15
A game of chance consists of spinning an arrow which comes to rest in one of the six equal sectors as shown in the given figure. A person spins an arrow once. What is the probability that the person: (i) wins a laptop? (ii) does not get a chance to spin again?
1/6 and 5/6
. In the below figure, there are two concentric circles, with centre O and of radii 5 cm and 3 cm. From an external point P, tangents PA and PB are drawn to these circles. If AP = 12 cm, find the length of BP.
PA = 12 cm, OA = 5 cm, OB = 3 cm
If the sum of the first four terms of an AP is 40 and the sum of the first fourteen terms of an AP is 280. Find the sum of first n terms of the A.P.
N2+ 7N