Need help to solve these very easy problems.

[marufdu07]

1. The outline of a sign for an ice-cream store is made by placing 3/4 of the circumference of a circle with radius 2 feet on top of an isosceles triangle with height 5 feet, as shown above. What is the perimeter, in feet, of the sign?
(A) 3 pie+3 SQRT3
(B) 3 pie+6 SQRT3
(C) 3 pie+2 SQRT33
(D) 4 pie+3 SQRT3
(E) 4 pie+6 SQRT3

2. If a motorist had driven 1 hour longer on a certain day and at an average rate of 5 miles per hour faster, he would have covered 70 more miles than he actually did. How many more miles would he have covered than he actually did if he had driven 2 hours longer and at an average rate of 10 miles per hour faster on that day?
(A) 100 (B) 120 (C)140
(D) 150 (E) 160


3. The sum of the first 100 positive integers is 5,050. What is the sum of the first 200 positive integers?
(A) 10,100
(B) 10,200
(C) 15,050
(D) 20,050
(E) 20,100



4. Forty percent of the rats included in an experiment were male rats. If some of the rats died during the experiment and 30 percent of the rats that died were male rats, what was the ratio of the death rate among the male rats to the death rate among the female rats?
A) 9/14
B)3/4

C)9/11
D)6/7
E)7/8


for No. 3 problem i got 15100
for No. 4 problem i got 3/7.

[julle286]

Question 2:

If he drives 1 h more with Speed + 5, he makes additional 70 Miles.

So:

1 * ( s + 5 ) = 70
s= 65

If he had driven 65 Miles per Hour ....... he would have made 70 add. MPH.

Ih he makes 2 more hours with 70 MPH; ---> 2 * 70 = 140 .

[e.cartman]

1. Ans (B) 3 pie+6 SQRT3
Assuming ice-cream cone shaped figure.
Top 3/4 circumference is 3/4 * 2*pie*2 = 3 pie.
Connect bottom triangle vertices to center of circle to get 90 degree central angle (because 1/4 circumference). So base is 2 root 2. half of triangle is root 2. Pythagoras to find hypotenuse.. root(27) is one side = 3root3. 6 root 3 for both sides.

2. (s+5)*(t+1)=st+70
so s+5t+5=70.
Find (s+10)*(t+2) - st
=2s+10t+20
=(2s+10t+10)+10
=70*2+10
=150
Ans D.

3. n(n+1)/2... Ans E

4. 0.3/0.4 divided by 0.7/0.6 = 9/14...Ans A.

[marufdu07]

Thanks a lot e.cartman

Today morning when i have pored those problem again, i could solve 1,2 & 4 except 3. But i was not so sure.

You reply makes me clear regarding this.

Cheers!!