Arithmetic
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PSAT Math › Arithmetic
If a car travels at 30 mph, how many feet per second does travel?
44 ft/s
2,640 ft/s
4,400 ft/s
440 ft/s
264 ft/s
Explanation
30 miles / 1 hour * 5280 ft / 1 mile * 3600 seconds / 1 hour = 44 ft/sec
There is a 5 to 3 ratio of red marbles to green marbles in a bucket. How many red marbles can be in a bucket of 40 marbles?
Explanation
In this problem, we use a proportion to solve for the number of red marbles in the bucket. Since the ratio is 5 to 3 we can set up a proportion of the red over total where the total is (red marbles + green marbles). We then set this proportion equal to 
Three hens each lay 20 eggs for a farmer. Two-fifths of the first hen's eggs are brown. One-fourth of the second hen's eggs are brown. Seven-tenths of the third hen's eggs are white. What percentage of all the eggs are brown?
Explanation
The first hen lays 8 brown eggs: 2/5 * 20 = 8
The second lays 5 brown eggs: 1/4 * 20 = 5
The third lays 6 brown eggs: 3/10 * 20 = 6
Add up the brown eggs and divide by 60, the total number of eggs:
19/60 = 0.31666667 = 31.67%, or 32%.
If a car travels at 30 mph, how many feet per second does travel?
44 ft/s
2,640 ft/s
4,400 ft/s
440 ft/s
264 ft/s
Explanation
30 miles / 1 hour * 5280 ft / 1 mile * 3600 seconds / 1 hour = 44 ft/sec
simplify: 0.2 ÷ 0.04
5
0.005
0.05
2
0.02
Explanation
0.2 ÷ 0.04 <- easiest way to approach is to move the decimal to the right (the same amount of spaces on each side) so that the decimal disappears
since 0.04 has 2 spaces and 0.2 only has 1, move the decimal 2 spaces to the right on each side
0.2 ÷ 0.04 = 20 ÷ 4 = 5
The price of a computer is reduced by 1/8. The new price is then reduced by 1/6. What fraction of the original price is the current price?
1/48
1/24
35/48
23/24
13/48
Explanation
Let the original price = p.
After the first reduction, the price is (7/8)p
After the second reduction, the price is (5/6)(7/8)p = (35/48)p
If x = 1/3 and y = 1/2, find the value of 2_x_ + 3_y_.
13/6
1
2
6/5
5/6
Explanation
Substitute the values of x and y into the given expression:
2(1/3) + 3(1/2)
= 2/3 + 3/2
= 4/6 + 9/6
= 13/6
simplify: 0.2 ÷ 0.04
5
0.005
0.05
2
0.02
Explanation
0.2 ÷ 0.04 <- easiest way to approach is to move the decimal to the right (the same amount of spaces on each side) so that the decimal disappears
since 0.04 has 2 spaces and 0.2 only has 1, move the decimal 2 spaces to the right on each side
0.2 ÷ 0.04 = 20 ÷ 4 = 5
There is a 5 to 3 ratio of red marbles to green marbles in a bucket. How many red marbles can be in a bucket of 40 marbles?
Explanation
In this problem, we use a proportion to solve for the number of red marbles in the bucket. Since the ratio is 5 to 3 we can set up a proportion of the red over total where the total is (red marbles + green marbles). We then set this proportion equal to
In a group of 20 children, 25% are girls. How many boys are there?
15
10
16
4
5
Explanation
Since 
