7th Grade Challenging Math
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7-51) Jenny mixes 2000 grams of sugar
water which has a sugar content of 10%. Several days later, the sugar content is 20%.
What is the weight of the sugar water now?

7-52) Adam mixes 1800 kg of salt water which has a salt content of 10%. Several days
later, the salt content is 15%.
What is the weight of the salt water now?

7-53) A farm has chickens, turkeys, rabbits and pigs. There are 60 pigs in all.
The ratio of chickens versus the sum of the other 3 animals is 1/4. The ratio of
turkeys versus the sum of the other 3 animals is 2/13. The ratio of rabbits
versus the sum of the other 3 animals is 4/11. How many animals in all are there
on the farm?

7-54) List the following fractions from the
smallest to the largest (left to right).
2015/2016; 2016/2017, 2017/2018

7-55) Calculate
(1+1/9)*(1+1/8)*(1+1/7)*(1+1/6)*(1+1/5)*(1+1/4)*(1+1/3)*(1+1/2)

7-56) Calculate
(1-2/9)*(1-2/8)*(1-2/7)*(1-2/6)*(1-2/5)*(1-2/4)*(1-2/3)

7-57) When 391
is divided by a two digit number, the remainder is 6. How many such two digit
numbers exist?

7-58) When 265 is divided by a two digit number, the remainder is 5. How
many such two digit numbers exist?

7-59) Jefferson School has a math club and a science club. The ratio of students
in these
two clubs is 4:5 (math : science). If 10 students from the science club moved to
the math club, then the two clubs have same number of students. How many
students are there in both clubs initially?

7-60) Matthew is 5
feet tall. He is standing next to a flag post on a sunny day. Matthew's shadow
is 3 feet long. At the same time, the shadow of the flag post is 15 feet long.
How tall is the flag post? (1 foot is 12 inches.)

More challenging math problems for seventh grade:
1-5 6-10 11-15 16-20 21-25 26-30 31-35
36-40 41-45 46-50
51-60
61-70
71-80
81-90
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