18. How many odd 3-digit numbers have the property that their digits, read left to right, are in strictly increasing order? 相关知识点: 试题来源: 解析 解:符合要求的三位数的十位数字只能是2~8,下面进行分类计数。 (1)口2口的有1 ×4=4(个); (2)口3口的有2 ×3=6(个); (3)口4口...
If the middle digit is the average of the first and last digits, twice the middle digit must be equal to the sum of the first and last digits. Doing some casework: If the middle digit is , possible numbers range from to . So there are numbers in this case. If the middle digit is...
if there are ?x? possible outcome to an event independent of the other and ?y? possible outcome to another event, then the total number of outcome pairs of both of them taken together will be x*y.Answer and Explanation: To find: The count of 3-digi...
They add nothing to the product. We are now about to see that we can do arithmetic only with whole numbers -- and then correctly place the decimal point.3. How do we multiply decimals? .2× 6.03 Ignore the decimal points -- do not align them -- and multiply the numbers as whole ...
Class 11 MATHS How many 3-digit numbers can be formed f...How many 3-digit numbers can be formed from the digits 1, 2, 3, 4 and 5 assuming that(i) repetition of the digits is allowed?(ii) repetition of the digits is not allowed?
How many three-digit numbers are there that have the sum of their digits equal to 10?. 相关知识点: 试题来源: 解析 54.. When the hundred digit is 1:109,118,127,⋯,190,there are 10 numbers; when the hundred digit is 2:208,217,226,⋯,280, there are 9 numbers; when the ...
How many different three-digit numbers can be formed with the digits 1, 2, and 3 if each digit can be used more than once in each number?相关知识点: 试题来源: 解析 (1) 6. (2) 6. (3) 27. (1) 6: 123, 132, 213, 231, 312, 321. (2) The digits in this question cannot be...
We place 2 on top of the long division sign above 3: $$\require{enclose} \begin{array}{rll} 2\phantom{0} \\[-3pt] 5 \enclose{longdiv}{{\color{Blue}{13} }5}\kern-.2ex \\[-3pt] \end{array} $$ Then multiply 2 and 5: $$2 \times 5 = 10 $$ We write the resul...
3 digit numbers that can be formed using the digits from 1 to 9. Required number of 3-digit numbers = arranging 3 digits with the total number of 9 digits. = 9P3 = 9×8×7. C is the correct answer.
This lesson discusses the process of multiplying one-digit numbers. It shows you how to find the correct answer using skip counting,, a...