(1).
St.1 is sufficient. say n = 10a + b, then according to statement n = a*(10+q) because a is a factor of b. Therefore n cant be prime as a>2.
St.2 is insufficient. With 2 as tens digit n could be a prime (23 or 29) or not; there's no way to confirm without info on units digit.
A is the ans.
(2).
No info in the stem.
St.1 is infufficient. The other 2 angles might be 90 deg as well; there's no way to tell.
St.2 is insufficient. We cannot comment on the sum of these angles yet.
Only after combining the info in both st. we know that the sum of the angles mentioned in st.2 is 180 deg (sum of all angles in quad is 360). Then we get one of the angles as 60.
C is the ans.(3).
Plain arithmetic. We obviously need both st. coz to get some info on each of the variables. Add the inequalities to get x + y < 73/72. Clearly, x+y could lie between 1 and 73/72, hence the statements are inconclusive even when combined.
E is the ans.
(4).
To answer this, one would need, in addition to the given statements, an inequality purely in terms of z and xy. We cannot derive it from the given statements.
E is the ans.
(5).
In order to calculate just the avergage, we don't need the exact no. of each of the tkt types sold. Just the ratio will do. You may verify this by assuming the no. of children's tkts sold as 3x and no. of adults tkts sold as 2x. You would realise that in the final expression of average, x disappears.
Hence, St. 1 is sufficient.
St. 2 is insufficient. It says nothing about the no. of children's tkts sold.
A is the ans.
(6).
Obviously we need both sts. Draw a Venn diagram: Cows is the smallest circle. Lions is the bigger circle containing Cows circle. Goats is the biggest circle containing both Cows and Lions circles. Clearly some goats are not cows.(7).
St.1 is insufficient. This only tells us that he'll finish other chores within 55 mins. Altho imp piece of info, we need to know more.
St.2 is sufficient by itself coz irrespective of him being able to finish other chores well in time to put away the dishes, he'll still fall short of 2 mins.
B is the ans.
(8).
St.1 is clearly insufficient. You can create infinite lists of 15 nos. with sum as 60 (rem, there are no contrainsts on the numbers- they may be negative or fractions etc.)
Before considering any argument seriously for answering this question, it is useful to think in this direction : Is atleast one of the nos. in the list not equal to the others?
Now consider st.2. Lets assume atleast 1 no. is diff. Now we can see an immediate contradiction with st.2. Inclusion or exclusion of this particular no. in a set of 3 will cause the sums to be diff. Therefore our assumption was wrong. All nos. are equal. St.2 is sufficient.
B is the ans