Question

SAT 数学题 帮忙解答下

if 3 more than x is 2 less than 9 , what is the value of x ？

if 4 bags of flour with an average (arithmetic mean)weight of 15pounds are put onto a shelf with 45-pound bags of flour , what is the average weight , in pounds of all 8 bags on the shelf ?

a certain ice-cream parlor offers 6 different toppings for sundaes . how many combinations of 2 different toppings from those offered are possible ?

if one of the positive factors of 40 is to be chosen at random , what is the probability that the chosen factor will not be a multiple of 10 ?

the length of each side of an equilateral triangle will be tripled to create a second triangle . the area of the second triangle will be how many times the area of the original triangle ?

when the positive ingeter x is divided by 5 , the remainder is 3 , what is the remainder when x+19 is divided by 5 ?

Answer 1

1. x+3 = 9-2, x=4

2.（4×15+45）/8= 13.125 pounds

3. 组合，C(6,2)=15

4.40的正因子有：1，2，4，5，8，10，20，40
因此，取到10的倍数的概率为3/8

5. 9倍，问的是等边三角形边长*3，则面积是原来的多少倍

6. x/5=y+3,
so,x=5y+15
x+19=5y+34=5*(y+6)+4,so the remainder is 4

Answer 2

4
13.125
15
9/10
4
2