Basic Numeracy/Quantitative Aptitude

Detailed Solution

233. The best answer is D.
The gender of the first-born is insignificant since we want all children to be of the same gender no matter if they are all boys or girls. The probability for the second child to be of the same gender as the first is: ½. The same probability goes for the third child. Therefore the answer is ½ x ½ = ¼.

234. The best answer is D.
The coin is tossed three times therefore there are 8 possible outcomes (2 x 2 x 2). We are interested only in the three following outcomes:
(0,1,1), (1,0,1), (1,1,0).
The probability requested is 3/8.

235. The best answer is A.
We want to make a 3-flower garlands, each should have three colors of flowers in it.
There are two different types of blue and two different types of red.
The options are (2 blue) x (2 red) x (1 yellow) = 4 options.

236. The best answer is A.
If 1/8 is the probability of drawing a blue ball then there are 40/8 = 5 blue balls in the jar. And with the same principle there are 8 red balls and 4 green ones. 40 – 5 – 8 – 4 = 23 balls (yellow is the only color left).

237. The best answer is A.
Since we want to draw at least one red ball we have four different possibilities:
1. Drawing blue-blue.
2. Drawing blue-red.
3. Drawing red-blue.
4. Drawing red-red.
There are two ways to solve this question:
One minus the probability of getting no red ball (blue-blue):
1-2/5 x ¼ = 1-2/20 = 18/20 = 9/10/
Or summing up all three good options:
Red-blue --> 3/5 x 2/4 = 6/20.
Blue-red --> 2/5 x ¾ = 6/20.
Red-red --> 3/5 x 2/4 = 6/20.
Together = 18/20 = 9/10.

1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
21	22	23	24	25	26	27	28	29	30	31	32	33	34	35	36	37	38	39	40
41	42	43	44	45	46	47	48	49	50	51	52	53	54	55	56	57	58	59	60
61	62	63	64	65	66	67	68	69	70	71	72	73	74	75	76	77	78	79	80
81	82	83	84	85	86	87	88	89	90	91	92	93	94	95	96	97	98	99	100
101	102	103	104	105	106	107	108	109	110	111	112	113	114	115	116	117	118	119	120
121	122	123	124	125	126	127	128	129	130	131	132	133	134	135	136	137	138	139	140
141	142	143	144	145	146	147	148	149	150	151	152	153	154	155	156	157	158	159	160
161	162	163	164	165	166	167	168	169	170	171	172	173	174	175	176	177	178	179	180
181	182	183	184	185	186	187	188	189	190	191	192	193	194	195	196	197	198	199	200
201	202	203	204	205	206	207	208	209	210	211	212	213	214	215	216	217	218	219	220
221	222	223	224	225	226	227	228	229	230	231	232	233	234	235	236	237	238	239	240
241	242	243	244	245	246	247	248	249	250	251	252	253	254	255	256	257	258	259	260
261	262	263	264	265	266	267	268	269	270	271

Passage Reading Verbal Logic Non Verbal Logic Numerical Logic Data Interpretation Reasoning Analytical Ability Basic Numeracy About Us Contact Privacy Policy Major Tests FAQ

---