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What can you between 7 and 8 so that the result is greater than 7 and less than 8?
7.8
If 7 cIts kill 7 rats in 7 minutes.How many would be needed to kill one hundred rats in 50 minutes?
7 Cat ----- 7 Rats 1 rat ---- 7 mins 100 rat ---- 7 x 100 = 700 mins 700/50 = 14 Cats
In a race, the man who came 16 places in front of the last man finished 3 places ahead of the man who came 7th. How many contestants were there?
1 to 20 constant
A fraction has the denominator greater than its numerator by 6. But you add 8 to the denominator, the value of the fraction would then become 1/3. Can you find this fraction?
7/13
A car travels from A to B at a speed of 40 mph then returns, using the same road, from B to A at a speed of 60 mph. What is the average speed for the round trip?
T = x / 40 + x / 60 = 100 x / 2400 = x / 24 The average speed is given by 2x / (x/24) = 48 mph
A rectangle field has an area of 300 square meters and a perimeter of 80 meters. What are the length and width of the field?
length L = 30 meters and a width W = 10 meters
The numbers x , y , z and w have an average equal to 25. The average of x , y and z is equal to 27. Find w.
w = 19
I am an odd number. Take away one letter and I become even. What number am I?
Seven
Sally is 54 years old and her mother is 80, how many years ago was Sally’s mother times her age?
41 years ago
There is a three-digit number. The second digit is four times as big as the third digit, while the first digit is three less than the second digit. What is the number?
141
How to get a number 100 by using four sevens (7’s) and a one (1)?
Answer 1: 177 – 77 = 100 ; Answer 2: (7+7) * (7 + (1/7)) = 100
